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ADVICE WANTED!   July 31, 2002
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characteristics of specific granite
specific granite, specific marble, other stones

Q 2359: Verde Butterfly versus Verde Lavras for a kitchen countertop. The granite dealer/importer suggested the Lavras because it is a denser, "less fragmented" stone. I like the Butterfly precisely because of the fragmented look (slabs I looked at had gold veining, black, and few burgandy spots). My question is, "Can I go with my favorite, Verde Butterfly?" Or, would it be a bad choice for a countertop? Karen, July 31, Reply 
R1: Dear Karen: If you accept the fragmentation, go for it! It's one of the best materials for kitchen countertop that money can buy.  Maurizio, USA,
Q 2355: I've just ordered peacock green granite for my kitchen countertops. Did your lemon juice test and it wasn't absorbed at all. Is this a good dense stone and should I seal it Thanks, PK., July 30, Reply
R1: Dear PK: My wallet bleeds while I'm telling you this: No, don't bother sealing it! Maurizio, USA,
Q 2352: What do you recommend for honed black granite (Indian Premium)? Thanks, Susan, July 30, Reply
R2: Never. Don't even think about it. Mike, USA,
R1: Dear Susan: Recommend? Just get rid of it! It's only money, after all, and your mind 
welfare is worth more than that, I think! You can read several posting about honed black granite (Indian Premium, or what-have-you) by scrolling down this page and going into previous pages. They're all soaked with tears!
Maurizio, USA,
2326: We are looking to use a black "granite" for a kitchen counter/ island sink top in an Australian house we are building. Is the local product - Austral black "granite" as reliable as "nero assoluto" from South Africa, particularly from the point of view of avoiding stains and damage (assuming that it is not sealed)? Is there a big difference in cost between the two stones? Ruth, Hong Kong. July 28, Reply
R3: Dear Ruth, your mentioned AUSTRAL BLACK, is gabbro, similar to NERO ASSOLUTO BELFAST from South Africa, but not such known. But you have even closer stone of the type - ABSOLUTE BLACK or SUPREME BLACK or SHANXI BLACK from China. I suppose this Chinese stone is cheaper than imported stones. Daniel, Slovakia,
R2: Dear Ruth: Run my little lemon juice test and you'll be able to tell! Maurizio, USA,  
R1: Dear Ruth, Black granite is certainly a good choice for kitchen tops because of their 
high density, low degree of absorption, and absence of quartz. The Australian "Austral" is a coarse-grained gabbro from Black Hill, east of Adelaide with occasional whitish flares or clouds. This distinguishes it from the higher-grade "Imperial" which should be more uniformly black and is therefore commonly used for monumental purposes. Nero Assoluto is a non-specific name given to black granites from a number of places but more often than not denotes an origin from South Africa and/or Zimbabwe. It tends to be finer-grained and closes well but occasionally also has some textural variation. Given that both are in the upper price range, have you considered some of the very high grade, very fine-grained black granites from India and Shanxi (China). Dr. Hans, Australia,
Q 2292: We wish to put granite countertops in our new home, under construction. We went to the slab yard our builder works with and found two very different stones, both of which interest us. One is called "New Venetian Gold" which is a light stone with some dark brown spots/streaks. The other is called "Forest Blue" which I believe is from South Africa. It's a medium/dark green with blue flecks and looks very nice. Unfortunately, we were unable to obtain scraps of these stones to test as you recommend. Have you heard of these stones, and do you have any opinions on them? I hope you don't mind a quick comment Michael, July 25, Reply
R2: Dear Michael, FOREST BLUE is from South Africa. It is granite s.l., but petrographically looks like gabbro. Daniel, Slovakia,
R1: Dear Michael: As a rule, I always urge people to go somewhere else if they can't get two of lousy pieces of scrap! New Venetian Gold is a good choice, but does need to be sealed. I don't know much about the Forest Blue, but I've heard that is quite dense. Anyway, I wouldn't dare to select it without a piece of scrap to fool around with. Maurizio, USA, Expert Panelist
Q 2284: I am looking for granite for Island top. I like Baltic Brown but am getting different answers regarding its characteristics. Is it a hard granite? Does it have pits in it? How absorptive is it? Would this be a bad choice in granite type? Could you recommend better choice with similar color characteristics? Susan, July 23, Reply
R1: Dear Susan: I urge you to read the posting No. 2278 below by Monica and my answer to it. Yes, Baltic Brown does have small pits and fissures, like many other "granites". Maurizio, USA,
Q 2253: I am interested in a stone called Azul Macauba to be used as a vanity counter in a bathroom. One person told me this was a granite, the other told me it was a marble. Which one is it? Is it a suitable stone for a bathroom vanity counter? Can you give me an idea of what I should be paying for this type of countertop for a 58" counter, installed?  By the way -- what is the difference between marble and granite? Thanks very much. Napers, July 18, Reply
R2: Dear Napers: I don't know exactly what kind of stone the Azul Macauba is, but I do know it's neither, although it's traded as granite. About the difference between marble and granite,Check the library in this site. encyclopedia, or your stone retailer. They know a whole shipload about stone all right!!! Maurizio, USA,  
R1: Dear Napers, Azul Macauba is neither a marble nor a granite - it is a quartzite consisting mostly of quartz and a blue mineral called dumortierite. It has a fairly high imbibition coefficient (rate of water absorption) of about 0.6%, which means that it is very absorbent. This means that any liquids like soaps and shampoos will be readily absorbed. This results in a wet-look stain. If any liquids are spilt on the vanity with a colour, the chance of discoloration is high. But because the rock is quite hard and fairly resistant chemically, common cleaning and/or poulticing methods will often work and not be detrimental to the appearance of the stone. However, because it is quite absorbent there can be other problems with this stone. 
A recent investigation of conspicuous brown staining on the surface of an Azul Macauba vanity top concluded that the 25mm thick stone absorbed the oils in the glue used to bond the stone onto a vanity cupboard frame made from customwood / craftwood. Whether the brown stain came only from the glue or from a reaction between the glue and the manufactured wood remains uncertain. There might also have been an additional contribution to the problem by the housekeeper who applied a solvent to the sealed surface and successfully but only temporarily removed the stain. This solvent might have reacted with either the glue or the wood thereby releasing more brown tannins or oils. One important consideration is that despite being sealed with a "high quality sealer" the solvent rapidly penetrated the stone and dissolved/removed the stain. What does this say about the sealer, or for that matter, about the stone?? Choose your application carefully especially  when it is one of the more expensive stone products that you can buy. As for the differences between marble and granite, there are many. Basically marble is usually a calcareous rock whereas granite is typically siliceous. Marbles are generally quite soft (can be scratched with a coin or a key) whereas most granite is relatively hard and therefore scratched with difficulty using household items. Being calcareous, marbles are chemically reactive to acids such as hydrochloric acid (used in pools) and even relatively weak acids such as acetic (vinegar). Marbles and limestone react with anything acidic such as wine, carbonated drinks such as champagne, fruit juices, and acid rain, and are even slightly  reactive to drinking water when the pH is lower than about 5. Granite is fairly resistant to all acids except hydrofluoric acid (HF) which thankfully is not readily available. Marbles originated from limestones (most of which are sedimentary rocks) whereas most granites are of igneous origin (partly molten). Dr. Hans, Australia,   
Q 2194: I am interested in a granite countertop for my kitchen and found your website very useful. Although, I like light colored granite, I am concerned it may get stained. Is the darker granite less absorbent? I like St. Cecilia, Gold Venetian, Verde Lavaras, and Atlantic Blue Granite. Is there a listing of granites that are best for kitchens? Linda, July 9, Reply
R1: Dear Linda: Verde Lavras and Atlantic Blue are excellent choices. Santa Cecilia and Gold  Venetian are borderline, in my book. None of them is a granite, of course! Maurizio, USA,  
A 2162: We are interested in Santa Cecelia granite. We have seen a sample which appears to have a lot of purple dots that look like cigarette burns throughout the granite. These dots seem softer than the rest of the granite and are both porous and rough. Is this a common characteristic of this granite? Claudia, July 5, Reply
R1: Dear Claudia: Yes, it's the "nature of the beast" Maurizio, USA,
A 2157: Blue Granite is the state stone of South Carolina. I was wondering if it can be used for countertops? If yes, then how do I find a source? Dobrenen, July 4, Reply
R1: Dear Dobrenen: One learns something new every day!
Of course, I never heard about that particular stone; therefore I have no answer to either one of your questions.
A 2047: Could you send me information on cleaning, care and maintaining Volga Blue granite? Also, what are your thoughts on the quality of Volga Blue? Wayne, June 12. Reply
R1: Dear Wayne: By the way, Volga Blue is indeed an excellent choice. I love that stone!! Maurizio, USA
 
A 2031: I have had two homes with 'granite' in each and I am on my way to the third. We want 'granite' again and were offered Rosa Perrino, Santa cecilia, Ubatuba, Verde Ubatuba, Baltic Brown, and Luna Pearl, all for the same cost. Are any of these real granite or am I going to have a maintenance nightmare with them? That is all I really want to know, you seem to have the 'right' answers and I need some help!  Sincerely, Dave, June 8. Reply
R1: Dear Dave: Luna Pearl and Rosa Porrino are true geological granite. (Actually, Luna Pearl -- a.k.a as Bianco Sardo is THE granite!) They are absorbent, but their absorbency is limited and can be easily controlled by applying a good-quality impregnator / sealer for stone. All the other stones you listed are not granite, but, with the exception of the Santa Cecilia, I consider them "better" than true granite for all the intents and purposed of a kitchen countertop. They are all quite dense and, most likely, require no sealing at all. I consider Santa Cecilia "borderline" in my book. Its absorbency rate -- though still controllable with a good impregnator/sealer applied several times over -- is approximately twice as much that of true granite. Maurizio, USA 
 
A 2028: I am very interested in new countertops in my kitchen made of Barracuda Blue granite. In your experience, what is the absorption rate of barracuda blue? Also, I have seen one person note that it is subject to fissures. Is this true? Should this be a matter of great concern? Jim, June 7, Reply
R1: Dear Jim: Never heard of that stone. Natural fissures are a common occurrence on many a "granite" and usually don't represent a concern, at least from a structural point of view. Maurizio, USA 
 
A 2014: What type of stone is Giallo Veneziano? Does it go under a different name? Is it a type of stone that would absorb stains? How would you compare the Peacock Green and the Ubatuba, and Pocono Green which one would you pick at first choice for a honey color kitchen with dark brown trim? Something nice and I shouldn't have to worry about staining? Please reply I am very confused what to do. Thanks, Sruli, June 4, Reply
R1: Dear Sruli: "Giallo Veneziano" is traded as granite (yeah, right!). It's rather absorbent and will require some serious sealing before using it. I don't know "Pocono Green", but the other two stones you've listed are a much better choice than "Giallo Veneziano" from a maintenance point of view. They are both much denser and require no sealing at all.  Maurizio, USA 
A 1983: I'm trying to find out from others who have Cambrian black granite installed in their kitchens, how they like it. Does it show dust and fingerprints easily? How about staining and lustre? Scott, May 29, Reply
R1: Dear Scott: Cambrian black -- an Anorthosite from Canada -- is one of the best stones that money can buy for a kitchen countertop. It will show dust and fingermarks like any other polished dark stone, but it won't stain. Do NOT have it sealed.Maurizio, USA
1910: We recently purchased a new home and had Uba Tuba granite countertops installed in our kitchen. I am struggling with routine care as the countertop never appears to be completely clean after use. It shows every fingerprint, drop of water and sponge streak. In fear of damaging the surface, I have only cleaned with water (we've only been in the house one month). I am seeking advice on daily routine clean-ups, as well as, preventive maintenance. I've read that sealers/impregnators (not sure the difference between the two) are not to be used on certain types of granite. How do I determine if mine requires sealant or impregnator and what kind? Any advice you can provide on the care of my countertop is greatly appreciated. This is the first time I've had granite and I want to take good care of it. Thanks, Renee, May 15.
R1: Dear Renee: I can see that your fabricator -- as usual -- didn't supply you with much intelligence about the subject of routine cleaning, did they! Maurizio, USA
 
A 1906: We recently had granite countertops (a color called 'Paradiso' which contains a combination of black, grey/white and reddish brown colors) installed in our remodeled kitchen and got the "we sealed it at the shop" answer mentioned elsewhere in your archives. I tried the lemon juice test on a piece of scrap and it appears to have passed. However we have noticed 2 things that have us slightly concerned and would like some expert opinions on.
First, although it passed the lemon juice test (no indication of absorption or damage to surface after 2 minutes) I did notice some minor discoloration to the darker areas of the countertop where a bottle of oil leaked a bit and sat for a while. I intend to try the poultice to clear up the spot but I am curious, does this mean that I should consider an impregnator despite the lemon juice test?
Secondly, my wife in particular has seen other signs of apparent staining/discoloration and is concerned about the appearance of pores in the surface (tiny pits that can only be seen when viewed nearly edge on with light reflecting off the polished surface.) Is this also an indication of a possible need for an impregnator.
We are complete novices and are not extremely confident in the answers we may get from our manufacturer after the response from the fabricator/installer and I appreciate the honesty and integrity I have seen in the responses on your site. Thanks in advance, Ray, May 15. Reply
R1: Dear Ray: If it did absorb oil, then it does need to be sealed with a good-quality impregnator. No matter what, however, it's never a good practice to leave oil or butter or margarine sitting on the countertop for a long period of  time.
The pits are natural occurrences and you shouldn't worry about them. No, an impregnator / sealer won't do anything about them. Maurizio, USA
A 1888:I was reading with interest your answer to a query about nero assolute granite. I am just about to order some granite for a kitchen island. I'm leaning toward the Nero Assoluto for two reasons. First, I like the look of black granite. Second, I can't afford to do the rest of my counters at the same time so I thought a relatively grainless granite would be easier to match that a more elaborate granite. However, reading the Q&A banter, it seems the absolute blackness makes staining more noticeable. Is this a common problem? I would also like to know whether fading is an issue. I have read somewhere that suppliers have been known to dye granite to make it blacker than it really is. Steven, May 15.Reply
R2: Dear Steven: Nero Assoluto (the real thing) is a Dolerite from South Africa. Nobody can 
"doctor" it with the application of a dye. It's an excellent choice. Other black "granites", mostly Gabbro, are excellent too, e.i., Black Jet and Black Galaxy from India (no "doctoring" possible on those, either!). 
But, while the criteria of your choice is quite smart (a solid black stone is easy to match even years down the line!), your fear is not without ground. Unfortunately, some "black granite" are, in fact, "doctored". To find out if a "Black Absolute" has been "doctored", rub a clean rag soaked with acetone over a scrap piece of it. That will tell you for sure!! Maurizio, USA
R1: Dear Steven, Nero Assoluto is both a generalized and specific latin name given to black
granites. The anglicised version is absolute black. They have a number of major sources - South Africa, Zimbabwe, India, Sweden, China, and to a lesser extent Australia. Most fine-grained black granites are good quality - because of their high quality of polished finish, paucity of deleterious minerals, lack of alteration, a lack of mineral orientation, an isotropic
structure, and few micro fractures. These properties combine to give the rock high strength and a low imbibe coefficient (absorption) - ideal for kitchen bench tops. You can't do better than a rock of this type. Sure, it makes spillages and dirtiness more noticeable - but that is not staining.
You do not have to seal good quality black granite! And be aware that some doctoring does go on in the stone trade. The application of certain oils and other products can darken the stone temporarily and make it look more impressive. However, such treatment will lead to a fading within weeks or months. This artificial treatment can be checked by the application of
acetone (or similar volatile hydrocarbon solvent) and a bit of elbow-grease. If some colour shows on the white material that you have used go elsewhere for your granite. Also be aware of the resin treatment of certain granites. I have just investigated and described this type of rock and Black Galaxy from India to which resin has been applied. Check the clarity and sharpness of some reflections (e.g. trees). I don't like it but then some consumers will. Incidentally, most of the fine-grained black granites are dolerites that have been contact metamorphosed and many have weird and wonderful reaction phenomena under the microscope. Dr. Hans, Australia
A 1885: We need to redo our kitchen and bathroom countertops. We have seen granite at called Baltic Brown. After reading your very informative website I am still confused. Are you saying that if it is a true granite and passes the lemon test that it will not need impregnator or a wax sealer? I do not want to be a slave to my countertops. Please give an answer. THANKS, Ann, May 15. Reply
R2: Granite is most excellent. The only acid that affects it is hydrophoric acid, this name is wrong, it sounds like that although. Anyway you mostly will not be working with this acid on the countertops. Granite is very porous, Solvent based Impregnator will rid you of staining in most cases as long as you are diligent in wiping up spills and moisture. Testing for adsorption every 3 to six months. Pour about an ounce of bottled water in different work areas of the counter top. If it stay puddled there for ten minute the impregnator is still working. If it starts absorbing the water, hand scrub the countertops with a neutral detergent, let the granite dry for at least 24 to 48 hrs. and impregnate again with the same product. Most of the time the impregnator last quiet a while and by doing these test will in most cases keep you ahead of the staining problems. Nothing say class and beauty like granite. Randy, USA.
R1: Dear Ann: Baltic Brown will be your faithful slave for the rest of your natural life, not vice-versa!! No sealer needed (here we go, I lose another sale!!). Maurizio, USA
A 1870: Hi- the info you provide on the website is great. I did the lemon juice test on a tan/beige colored "granite" that I was told was from India and called Golden Viera (?) It didnt stain immediately but did after 30 secs or a minute... In the granite yard the piece was outside and had huge water stains on the bottom from the rain, but the granite man said that's because it wasnt sealed yet It took me MONTHS to find this color/design and I love the look but don't want a high maintenance countertop, esp since I cook alot and have kids that dont clean up after themselves :) Will the sealer be the answer, and how and how often do I seal? Is there any other very neutrally beige/tan/taupy granite that has a look of marble that you know of. Thanks, Darlene,May 15.Reply
R2: Dear Darlene: The result of the lemon juice test the way you report it indicates that your "granite" is within those that can be controlled fairly well with a good-quality impregnator sealer. You should go for it. 
How often you should have the sealer applied depends on the make of the sealer. Some manufacturers recommend to seal every year (in this case we're usually dealing with Silicon-based sealers). Some others will tell you every 3 - 5 years (Silane-based sealers). Others, every 15 - 20 years (Ester-epoxy based sealers, my very favorite). The latest generation of sealers (Fluorocarbon-based) promises to last a long time, too, but that type of products are too new to venture any reliable frequency of application. Once you start with a sealer is advisable not to change brand for future applications: There could be compatibility problems. Maurizio, USA
R1: Dear Darlene: There are a number of beige-coloured granites on the world market. Many are coarse-grained and a bit weak (e.g. Venetian Gold), others have spots and alteration products, and some are swirly. A very boring (uniform), fine-grained granite is Brisbane Beige from Australia. Dr. Hans, Australia 
A 1855:I have just recently put down a Kashmir White floor down in my kitchen, and am getting Kashmir White countertop and backsplash. At looking at this website, it seems like I haven't made the best choice. Please advise how to clean the countertop and floors. I have seen you need to use soap and water. When you say "soap", what kind of soap are you referring to? Also, I don't believe my floors were sealed, and they have a brownish color in some of the tiles? What should I do about this? Thanks, Baine, May 14. Reply
R2: Dear Baine: Let me start out by saying that I feel deeply sorry for you. If you still can get out of your deal about the countertop, by all means DO THAT. No, you do NOT want to use soap (of any type or brand) on a polished stone surface. It will leave a film that will keep accumulating until it becomes plain, unsanitary scum. That said, even if with little hope, your "granite" has to be sealed to death with a good-quality impregnator sealer (please, leave my own sealer out of the picture. I really don't care to deal with those kinds of stones). Maurizio,  USA
R1: Kashmir White is an extremely porous material. For the floor you will need to get a polymeric finish for it and reapply frequently, I don't consider this something you can do  your self. Contact Maurizio for instruction and advice. If it is not too late. select another material for your kitchen counters. Regards, Steven, USA
A 1851: I am building a new home and would like to use granite counter top in my kitchen. I was shown a sample that was marketed as Chestnut Granite from India. I researched further and now believe it may be Sapphire Brown. Could you tell me if this is possible and if its is a good choice for a top. Will it need to be sealed? Also when you do your lemon test should it be done on the raw material or can you use the sample that is polished. Thanks. Mark, May 14. Reply
R2: Dear Mark: The lemon juice test must be run on the polished side. Maurizio, USA
R1: The sapphire brown is a good product. Test the polished side. Good Luck, Steven, USA
A 1830: email me relevant information, about natural stone quarried in San Antonio, TX & Austin, TX or surrounding areas. Types: water erosion &density factors that would pertain to pond & fountain or water falls. Yrubn, May 14. Reply 
A 1826: I'm building a new house. I just had my countertops installed this week. We chose Labrador Antique. It has great shade, colour, etc.. But I've found a rather big flaw on the island slab. It's a odd shaped black spot which is not polished. It's dull looking and rough. It looks similar to coal. Have you seen this before? Should I ask for a price reduction?? It's about 1 inch long by one half inch wide. Looking at the rest of the piece with a reflection, there are certain tiny dots (dimples) that are noticeable. Should the entire top be perfectly smooth without any defects? Mark May 14. Reply
R2: No this may not be a flaw. Labrador Antique has these inclusions. If you get a light and shine it on the black spot from various angles, do you see a blue or green crystal reflection?
Regards, Steven, USA
R1: Dear Mark: Without actually seeing it, it's hard to make statements, but my educated guess is that dark dull spot in the middle of the slab is not natural. I suspect that it's some sort of filler that had been applied in the factory (not at the fabrication shop). Should you accept it? ... There are no standards on how picky one should be, are there! ...A small reduction in price would seem more appropriate. Again, remember, all the above statements are olny assumptions. About the other flaws you indicate, they are typical of many a "granite", including the one you have, which, by the way, is an excellent choice. Maurizio, USA
A 1764: I am interested in Grigio Perla (Italian granite) for kitchen countertops. How does this stone perform in such an application? How easily does it stain, etch, crack, chip? how can I go about finding it? Thanks, Caroline. April 27. Reply
A 1747: I am ready to buy granite for my countertops and I know I want a green. My appliances are stainless steel and my cabinets are Golden Oak. I was looking at the Uba Tuba, however it has a lot of black in it. Is there a green granite with gold flecks and little to no black. I want them to appear a jade green- not black. My biggest problem is that you can't view the samples. The internet pictures all look different or it is too small to get the full effect of the stone. I would appreciate any advice. Mitchell, April 22. Reply
R3: Mitchell, It is such a coincidence that I am also deciding between Uta Tuba and Verde
Butterfly
for my kitchen counter top. The cabinet is made of beech and the color is golden yellowish color. So the color is same as your cabinet 
I was wondering what you have decided. I am thinking of going with the Verde Butterfly. It has more gold and white speckles. The speckles are really big. It looks really beautiful. The Uta Tuba has smaller speckles and the color is darker. Thanks, An, USA.
R2: Ubatuba is by far the most popular green granite in use today. To be fair, you should view the slabs that your fabricator has in stock or will be purchasing. We have had this material range from almost black with a lot of gold to olive green/blue with no gold. A related granite is Verde Butterfly or Mariposa which is also from Brazil. It has a larger crystal and is a deep green with gold. Good luck. Lynn, USA
R1: Try Verde Butterfly also known as Verde Pavao. Regards, Steven, USA
A 1731: I just spent the whole evening reading your advice to homeowners about various aspects of remodeling.
I am about to replace the old kitchen counter with a new one made of either granite or silestone. My esthetic choice is granite, although I do worry about stains that could become permanent. How about UBA TUBA, DAKOTA MAHOGANY, ALMOND MAUVE? are they true granites or are they reasonably resistant to penetration? What might be some good choices (dark color, no waves) that are least porous but wont break my pocket book? Helen, April 19.
R2: By maintaining your granite with a good penetrating sealer (impregnator) you will minimize staining. The darker materials you mentioned, Ubatuba and Dakota Mahogany, will by their dark nature show very little discoloration that comes from oils. Almond Mauve, on the other hand, will show the darkening with time that use of cooking oils and even oils from your hands will produce. Lynn, USA
R1: All your listed choices will provide a good counter. The Almond Mauve will require an impregnator. Regards, Steven, USA
A 1727: I have on order a large granite countertop. I chose and specified Belfast absolute black. I selected a slab at the importer which was classified as Absolute Black. The fabricator picked up and delivered Zimbabwe Black. They are pushing that these are in fact the same type stone and any absolute black, which Zimbabwe classifies as, can be substituted. That absolute black stones are so uniform they don't need a "selected stone" to fabricate. In fact the Zimbabwe is the premium of these stones. I feel I can see a difference in depth of color between Zimbabwe and the "absolute black" I selected. I am hesitant to enhance the color or use a colored polish, I want as maintenance free a solution as I can get. Any suggestions and can you clarify the difference between absolute black stones. FYI due to a great deal of stripped fading in the first stone that was delivered, this is actually a replacement countertop. Denise. April 18. Reply
R1: Generally I find the Zimbabwe version grayer than the Indian version. If you don't like it don't accept it. Further, if you have had trouble once, don't repeat the mistake of allowing the slab to be "doctored". Regards, Steven, USA
A 1726: I selected Bethel White granite from a supplier in Vermont for application as a slab countertop with 12 inch tiles (Bethel White granite) as the backsplash wall application. The slab has a series of small rust spots and I am hesitant to approve this material for delivery. The supplier suggested that I change to Impala Black slab granite and tiles (from Africa). I need to decide and I am concerned about the rust spots on the Bethel White and use of the granite tiles behind my professional, gas-burned cook-top. My intention is to run the tiles from the top of the counter to the ceiling. My granite knowledge is limited but I'm trying to learn - quickly! Can anyone provide some perspective for me? Lyenne. April 18.
R2: Well, It seems to be a black versus white quandary. If you don't like the white then don't approve the slabs or tiles. If you don't have a problem with Impala Black then I say use it. It is a very good stone for counters and splashes. Regards, Steven, USA
R1: Bethel White has, according to my knowledge, Pyrites which can rust with age. It has to be treated and maintained regularly. I can suggest a product without prejudice. Thomas, South Africa.
 
A 1719: I visited a stone merchant to pick out my granite slabs. I saw a slab named Santa Cecilia, took a sample home and did the lemon juice test. I don't "think" I saw any problems, but was wondering if you could offer any comments on the stone. Thanks, Laura, California, April 17. Reply
R1: It is a popular product in the US. It will require the application of an impregnator. Regards, Steven, USA
A 1714: Hello Maurizio, I'm doing your lemon test right now on my Giallo Veneziano sample.  I'm not sure if this sample has been sealed or impregnated.  The granite seems to darken very slightly, but the lemon does not get absorbed into the stone for quite some time (25 minutes and still counting). If I understand the test correctly, this should be a good choice.  Can you please confirm? Thanks, Teresa, April 16.
R2: The Giallo Veneziano is absorptive. It will need the application of an impregnator.
Regards, Steven, USA
 
R1: Dear Teresa: If it darkens, it means that it's being absorbed. In my opinion that particular stone is borderline, but - I must admit it - my standards are quite high! If sealed properly, you will enjoy your stone for years to come. Go for it! Maurizio, USA
A 1706: Hi, I'm thinking of using Madura Gold or Madura Gold Light granite for my kitchen countertops. Do you know if these are low absorbency granite, or even if they are a true granite? I don't have a sample so have been unable to perform your lemon test. Thank you for your time, your expertise, and your informative website. Melinda, April 14. Reply
R2: Dear Melinda: No they are not granite. If you can't get a sample to run the lemon juice test, go to another fabricator.   Maurizio, USA
R1: Dear Melinda, MADURA GOLD from India is migmatite - metamorphic rock with wave structure probably composed from quartz, feldspar, micas and limonite. I think it is suitable for countertop. Daniel, Slovakia
A 1699: I have intentions to buy absolute black for garden tables and received samples from India. This in polished and honed version; I did the test with lemon and it gives spots, but not with oil, coffee and tomato extracts. I did not have the intention that I gives much dirty spots and is easy to clean. Is there a difference in Indian or South African granite? What kind of oil can I use and is there another grey or black granite I can use? What kind of stone is most used for garden tabletops in the USA? Do you know Belgian hardstone? Very nice for garden tables, but sensitive to dirt so I am looking for granite as nice as Belgian hardstone, but better quality. Greetings, Marc, April 13. Reply
R3: In South Africa we have Rustenburg or also called Impala granite which is as well known as the Carrara Marble all over the world. The Rustenburg granite is an excellent material and does not have to be sealed. The material is available from our quarry. Thomas. South Africa. 
R2: Dear Marc: Well, which one produced spots with lemon? 
For all I know both the South African and the Indian (at least the one that I have in mind) are equally good, although geologically different, and neither should be effected by lemon juice, unless ... they have been "doctored". I've seen such a "nice" fraudulent procedure done mostly on Black Zimbabwe, but it is not to be excluded that it's been done on other "black granites" as well. Black Zimbabwe (which, as the name itself indicates, is not from South Africa) is actually a dark grey stone and, because of that, not very "sellable" as darker stones. So, here comes the unscrupulous slab manufacturer that applies a black "shoe-shine" sort of makeup to "make" the stone black. Acids, will remove that makeup, hence the "etchings" which is not on the stone, but on the applied-on finish. If one removes completely such finish and accept the natural lighter color, then it's a very enjoyable stone. 
None of the black "granites" I know of need to be sealed. So, the reasons fo the reaction to the lemon juice could also be the consequence of the presence of an impregnator-type sealer that has no business being there, and shows damages because it never got a chance to be absorbed by the stone (they are all very dense.) 
The other liquids that you tested confirm that the stone doesn't need sealing.  Maurizio, USA
R1: Dear Marc, The main difference between the two black granites is price. You can use any other dark grey or black granite for your intended purpose - all will need some maintenance if left out in the garden, especially under trees. For additional maintenance you could try a honed finish. As for Belgian "hardstone" - remember that beauty is in the eye of the beholder. If that beholder is a bit blind then many things are beautiful. And as for the oil that you could use try the extra virgin variety. (Dr. Hans), Australia
A 1579: What can you tell me about the quality (reputation) and care (and anything else you know) of "Tiger Skin" granite? I saw this and had to have it for my kitchen. Gina, March 22. Reply
R2: Dear Gina, your taste is excellent for TIGER SKIN is a beautiful stone. This gneiss from India is hard, resistant material. Losst of lustre can be in black streaks with mica accumulation, but it is a feature of this stone type. Daniel, Slovakia.
R1: Dear Gina: I've heard of it, but never saw it (or maybe I did, under another name!). The only advice I can give you is to use my little "lemon juice test", then draw your own conclusions. Maurizio, USA.
 
A 1562: I am considering Avanza countertops for my newly remodeled kitchen. I am not a friend of Granite - since the colors are not what I am looking for (white with silver flecks). What kinds of things do I need to watch March 20. Reply
R1: Sorry never heard of it. Many companies private label their stones to make identification difficult. I am sure you understand that this is a stone industry site, not Avanza ask them how to take care of it. Regards, Steven, USA,
A 1501: I need information on Gold Vyara. Is it a hard or a porous granite? Is it a good maintenance choice for kitchen countertops? Tom, March 8. Reply
R2: Dear Tom: Hard and porous are not related. For the suitability of the stone you mention as a material for a kitchen countertop, run my little "lemon juice test" (on the side bar), then draw your own conclusions. Ciao, Maurizio, USA  
R1: It is a porous stone and will need a good sealing process. It does tend to have fissures and hairline cracks but that is the beauty of the stone. I typically fabricate jobs using this material in the 8 - 10 slabs range per job. Customers love the softness and unique look of the stone. LkCmbr, USA
A 1499: I am trying to get information about Juparana Florenca for my kitchen countertops. Is this a good choice?  Thank you. Debbi, March 7, Reply

R1: Dear Debbie: Run my little "lemon juice test" on it (see side bar), then draw your own conclusions. Maurizio, USA

A 1475: I am considering using "Azul Aran" (aka "Blue Paradise") for my kitchen counters. However, I heard about it being prone to rust in water situations, because of metal in the stone. Is this a concern in the kitchen (versus the bath)? Will sealing avoid any risk of rust? No matter how careful you are, stuff happens (wet glass left overnight; leaking faucet). Ed, Feb. 26. Reply
R1: Azul Aran has gotten some bad press. It is a pretty stone and I would judge it on a block to block basis. If you leave a glass on the counter and it leaves a ring this small amount of moisture would not rust. I am not sure (Dr.Hans probably knows) but I don't think it is iron in the stone. I believe that some of it has pyrite and this can oxidize and be seen as rust. If you have the stone impregnated with several coats of properly applied impregnator it would probably prevent any oxidation. Regards, Steven, USAReply
A 1250: I could have an order for installation of Yellow St. Cecilia. I am doing a job near Boston, MA, USA. Owners only concern is gritty or flaking of granite counter for cooking surface. The problem is they have friends, who have this stone and when you run your hand over it your hand is full of what feels and looks like sand. This counter does not seal or clean and still flakes. Note this is not a true granite. I need to know if this stone is ever going to stop flaking. Would like to give more info, but tell me what you need to know? Mike Dec 11. Reply
R4: The areas in this stone that flake are the oxblood color spots. They are significantly softer than the the other parts of St. Cecelia. There are some varieties that have fissures and some surface pitting. This product is very absorptive. Consequently if they cook a lot, steer them into a different stone. Steven, USA
R3: THE REASON IS THAT THE STONES WERE UTILIZED SLABS FROM BLOCKS OF THE UPPER PART OF THE QUARRY, NOT PERFECTLY "STONED". THIS PROBLEM IS EASILY SOLVED WITH EPOSSIDIC RESIN ON THE SLABS BEFORE POLISHING, BECAUSE THE RESIN CLOSE ALL THE MICRO HOLES AND YOU HAVE A PERFECT SURFACE AFTER THE POLISHING. THIS IS THE NORMAL WAY WHEN YOU HAVE MATERIAL WITH SMALL HOLES ON THE SURFACE ; OUR SLABS DO NOT HAVE THIS PROBLEM, BUT IF THE CUSTOMER WANTS WE CAN DO IT, THE PRICE OF THIS PROCESS IS $ 15.00/SQ.MT. REGARDS. VINICIO, Italy,
 
R2: This granite should work for you in the kitchen, After installing clean & seal. Atkin, USA
R1: Quite honestly, I don't understand much your question. Maybe you were thinking at the cost of wiring your message, where they charge you by the number of words! Anyway, if the grading of the slabs is good, you shouldn't have any problem with that particular stone. Keep in mind that's not a true granite, and it does require massive doses of a good-quality impregnator-type sealer. Maurizio, USA
A 1176: Dear Sirs, Is Lillet granite slightly porous? Is this stone known under different names like "Alba Roso" or "Sunset Rising"? Have you ever heard of these types of granite? With best wishes, C. Francet, Nov 10.
R2: Dear Francet: Mmmmmmm .... "Sunset rising" .... That's a good one, all right!! No, I don't know. Run the lemon jiuce test to find out yourself about the absorbency and suitability (as material fo a countertop) of that particular stone. Maurizio, USA.
R1: Dear C. Francet, Lillet granite is slightly porous. Alba Roso or better Rosso Alba is Iranian marble, Sunset is granite from USA, maybe granite from India, Sunrise is Indian granite. Daniel, Slovakia.

MY GRIPE:  I am an end-user who contracted for the delivery of some Italian granite tiles, 60 mm x 60 mm x 3/4 worth some $ 80,000 in various colors, among them Blanco Pero or Blanco Pera. Delivery is almost complete. However, recently I have had reason to suspect that the granite tiles supplied to me did not come from Italy but from China. I have heard that this is happening particularly in Asia. Could you tell me if you know any quantitative and qualitative tests that I can use to determine if I have been duped? Would you also have an expert in the Asian region? Ayette, USA, Reply

R4: I think this is not BLANCO PERA but Spanish granite BLANCO PERLA. Daniel, Slovakia

R3: The only quantitative method to use is to check the physical properties of the stone such as density, absorption, etc. There are a group of stones from the Carrara and Massa section of Italy. When you buy such quantity, you may want to speak to the quarry to see if they remember the order. You probably want to use the Italian word for white-- Bianco, however. Ask what grade of marble you receiving is i.e. 1 - 4 and what group it is from. Expect the Italian variety to be Group A (very sound). Best of luck! Steven, USA.

R2:
It is very simple to find out if what you are supposed to have is what you really do have.  A petrographic analysis is straight forward and fairly cheap method of characterizing every rock.  It is a bit like DNA testing in that it is extremely unlikely that rocks from two different continents are identical in their mineralogy, texture, and structure.  However, it does have to be done by a specialist - preferably one in the stone game.  The "perpetrators" of any possible substitution might come back and say that the petrographic analysis is invalid because of natural variation in natural rock tiles.  This argument does not stand up scientifically.  If any
argument got more serious then there are many other somewhat scientifically more sophisticated methods for fingerprinting rock, e.g. isotopes.  So, all you have to do is get small pieces (20mmx10mmx10mm, or a little bigger) of the stones and have them analysed.  The hardest part is to get someone reputable who could supply you with a small piece of broken tile of the two genuine European stones so that they can be used as reference material. Hans, Australia
R1: A Spanish name for an Italian "granite" that's perhaps coming from China!... That gives a brand new meaning to the definition of international trade! I have no answer to your question. You may want to try with some University (Pennstate, maybe). All I can tell you is that Italy is, by far, the largest producer of dimensional stone in the entire world. The fact is, however, that the stones coming out from Italy are not necessarily quarried in Italy. Italian producers buy blocks from just about all over the world, they process them into slabs and / or tiles, then off they go! You may want to consider demanding the importer to disclose the exact location of the quarry for you. If they tell you the quarry is, in fact, in Italy, let me know where and I'll find out for you if they're telling the truth (I still have strong contacts over there!) Ciao and good luck! Maurizio, USA.

A 1079: I am getting conflicting information regarding the prevalence of fissures in Lagos Azul slabs. One supplier tells me that they are customary, and, of course, his slabs have a lot of fissures and pits. Another supplier tells me that Lagos Azul is generally very solid, lacking fissures.  Both suppliers' slabs have what appears to be black, tar-like, filler material, but both suppliers offer different stories about this material.  Lastly, how do you feel about using Lagos Azul for kitchen counters?  If you think its a bad idea, can you recommend a natural material that would complement Lagos Azul floor tiles? Thank you, Tom, USA, August 28, Reply

R1: For all I know Lagos Azul has a lot of unofficial grading. Some slabs are more solid than others. It much depends on the purchasing ability of the fabricator, and how much he's willing to spend. I never had the opportunity to test such material for absorbency and resistance to acids. But you can run a couple of easy tests yourself. Get a piece of scrap slab, take it home and spill on it some lemon juice. You need to check two things:
1. Does the juice get absorbed right away? (Producing dark spot within a few seconds of its application). If so, you know that the material is extremely absorbent. I personally wouldn't want it in my kitchen, if that were the case. But then, we're Italian and both my wife and I love to cook a lot! 

2. If it doesn't absorb readily, then you're in good shape as far as absorbency is concerned: A good-quality penetrating sealer will take care of that. After approximately a minute or so, wipe the lemon juice dry. If it left a dull spot where it was sitting, then you do not want that material in your kitchen, floor included. If not, it's OK. Good luck and Ciao, Maurizio, USA Contact 

Id 1003 USA: Can you tell me if Pietra del Cardosa is granite?  How will it hold for a kitchen counter top?  Will need special maintenance? Aug 23. Contact

R1: Pietra del Cardoso is Italian grey sandstone, not suitable for countertop because it is not polishable and contents calcite. Daniel, Slovakia

A 1051: Name It: I have often heard that India Black was best for art work on granite as it had a very fine grain and therefore the letter or image would give the best results for monuments.  However, some of these black stones appeared to have water marks running down the polished surface.  Is this suppose to happen on India Black or is this likely a lower quality of black granite?  Any info would be appreciated? Calvin, USA, July 21. Reply

R1: That's a lower quality. The best Indian blacks do not have this problem. See the Indian granites in our Stone Album. FindStone.
I went to the Indian granites and I thought "India Black" was a particular one in your photo album.  This is a name that I have seen listed with some dealers but perhaps this is a name they use to call all Indian Blacks.  And as you said in your earlier email some are of lower quality resulting in the dyes running out over time.  While there were several named blacks, which one is the finest grained one for use in monuments where this bleeding is less unlikely to be present. Is it Ratnasila Black?  Is there some kind of grading system in place one could look at to see photos of the various grained stones (course to fine grain granite).
Many thanks, Calvin, USA,

R2: Best thing to do would be to put your requirement in our site by filling the 'Put Advertisement form'. The lower quality ones are sometimes darkened chemically by unscrupulous exporters. If you see the articles in our Library (I think one called Defects) you will understand better. There is no grading system. Those in the industry know the different areas from which black granites are quarried and they know the quality from each such area. The best, for example, is from Kunnam in India and is thus known as Kunnam Black. FindStone,

A 1049: Is the Dynamic Blue as green as it looks on our computer. Is this a good countertop material. What other blue granite besides blue pearl do you recommend that would match an azul boquira porcelain floor? Tim and Kay, USA, July 9. Reply
R1: Dear Tim & Kay, I recommend you Brasilian blue material which match your porcelain floor, but this material is changeable and expensive. They are named: AZUL IMPERIAL, AZUL BOQUIRA or AZUL MACAUBAS. There are some hard blue materials like AZUL BAHIA or BLUE KING. They are less changeable but there is possibility of chemical damage - color change. Daniel, Slovakia

Q 973: What are all the minerals of Kazakhistan and exact location? Kamal, USA. May 9 reply

R1: The properties of fine grain black "granites' usually don't vary greatly in different directions so they don't really have a "grain" direction like wood. Regards, Jim, Australia.

A 954: Could you tell me the main minerals that make up Absolute Black? Simon, Australia, April 6. Reply
R1: I suppose the mineral composition because of great similarity with the materials (gabbros - dolerites) from South Africa, Zimbabwe and Sweden pyroxene and feldspar (Ca-plagioklase). The next not main minerals may be or not: magnetite, olivine, apatite, quartz, chlorite, biotite, amphibole, alkaline feldspar.
Daniel, Slovakia

A 929: What is the composition of black granite? What minerals are present?, Sollacks. USA, Feb 21, reply

R2: Black granite isn't really granite.  Its correct name is Norite.
A typical composition of 
5% K feldspar
50% Na feldspar
30% pyroxene
8% biotite
5% opaques
2% other
Regards, Jim, Australia

R1:
Dear Sollacks, There are many ways of answering this one depending on what sort of composition you mean (chemical, normative, isotopic, etc).  You will find many analyses of black granites from all over the world in "Journal of Petrology" and "Contributions to Mineralogy and Petrology" but you will need to go back to the early volumes (1960's -1970's) to get the best information.  You probably only want to know the mineralogical composition of black granites.  Most black granites (a term restricted to the stone trade) consist of 3 basic minerals - calcic pyroxene, plagioclase feldspar, and an iron oxide.  The pyroxene typically occurs in quantities of 20-35% and provides most of the dark coloration.  The feldspar is mostly a calcium-rich variety and typically occurs in quantities of 50-65%. The black iron oxide (titanomagnetite) or iron-titanium oxide (ilmenite) commonly constitute about 5-8% of the rock.  However, typically there are also small amounts of other minerals in most black granites including amphibole (e.g. hornblende, kaersutite) and a dark mica (e.g. biotite, phlogopite) and there is sometimes a greenish mineral called olivine. There can also be another pyroxene variety low in calcium (e.g. hypersthene, pigeonite). There is of course a wide variation even amongst  black granites - some are extrusive, some are high-level intrusive (hypabyssal) and some are plutonic.  All differ slightly in their mineralogical composition as well as in their texture, structure, and in the composition of their constituent minerals (this is what makes the science of rocks so fascinating).  Then there are black granites that have formed from other pre-existing, usually mafic rock types, through the processes of metamorphism.  Because metamorphism always involves an elevation of temperature and usually involves fluids a fascinating range of textures can be produced, as well as an assortment of new (prograde) minerals. There can also be reactions that produce secondary minerals such as chlorite, a host of other amphiboles, as well as epidote, talc, serpentine, and smectite clays.  Some of these reactions produce strange textures. Then depending on the composition of the fluids involved in the metamorphism it is possible to get a number of other minerals introduced (e.g. quartz, alkali feldspar, sulphides).  Because it is quite difficult to distinguish many of these minerals even for a scientist let alone a quarryman or stone processor, it is very important for a stone geoscientist (not a geologist) to analyze the stone petrographically to determine whether or not it contains any minerals which might cause problems in performance (serviceability) and durability of the stone.  This type of study can also tell a lot about the origin of the rock and provides information on its potential for development, its quarryability, and any problems which might be encountered in the future. I hope this enlightens you a bit on the mineralogy of black granites.  Dr. Hans, Australia


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