| ADVICE WANTED! | July, 2001 | |
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| Material Characteristics | Identify the Stone | |
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some specific type of product, do state so.
Advisors: Please
share your knowledge and expertise and give as detailed a reply as possible to
each inquiry. If you can offer some specific service or product, please mention
the type of service or the generic product-type with indicative prices. If you
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separate link.
A 1025: Where in the southeastern U.S. are slate and/or flagstone found naturally?
Hardesty, USA. June 27 reply
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 their 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 1006:
We are in the process of having a new home built. We contracted with the
builder to install Labrador Antique granite countertops in
kitchen. After installation we noticed what appeared to be prominent
cracks in several portions of the granite. It looks awful. The
granite yard had told us that these were veins but in one spot, the granite is
actually raised where there is a crack. We are wondering if cracks are
common to this type of granite? Brenda, USA. June 12 reply
R1: The
usual cause of dislocated cracks after installation relates to the
"superstructure" that supports the slab. In this case it is likely that the
kitchen cupboard framework has shifted or settled. This shift may only be
an 1/8 inch but this is could be enough to exceed the flexural strength of the
granite if the supporting span is too great. Use a straight edge (yard
rule) and check for bowing.
Jim
Man, Australia, Expert Panelist. Contact
R2: Dear Brenda: I am
really not familiar with the type of "granite" you mention. Well, maybe I am,
but I never heard that particular name (you see, many slab distributors call the
same "granite" with different names, so it's harder for consumers to shop them
around). Let's assume, however, that the name "Labrador antique" indicates a
labradorite-type of stone. If that's the case, I really can't figure out what
the problem you're reporting about is. For starters, veins are veins, not
cracks. A vein is either a mineral of a different color within the texture of
the stone, or a natural staining occurred some 200,000 years ago, or something.
In either case, there is not any interruption in the texture of the stone. There
are other natural flaws, however, that are called fissures. These are, in fact,
very tight cracks which are usually only a few inches long and barely detectable
-- if at all -- at the tact. In all my traveling I never saw a labradorite-type
of stone with any significant fissure in it. Labradorites are among the most
compact and uniform stones available and, because of that, they make one of the
best choices for a kitchen countertop. If you have what appear to be cracks, you
most likely have cracks that shouldn't be there and that natural are certainly
not. Ask the stone dealer to show you another slab of the same material with the
same type of severe cracking as yours. Do you understand where I'm driving to?
Good luck, and keep me posted. I'm really curious about this matter
of
yours.
Maurizio, USA, Expert Panelist. Contact
A 1005: I want to know more about sandstone, technical data, how and where to use it. Advantages and disadvantages, and how to look after it. (Industrial and domestic use.) Ewaldl, Zimbabwe. June 11 reply
e 1605 USA: I am looking to buy blue green quartzite from brazil 12x12
size 700 sq. mt. June 7 contact
A 998: Does absolute black
have a grain? Jill, USA. May 28 reply
R2: Dear Jill: Nope. Maurizio,
USA, Expert Panelist. Contact
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, Expert Panelist. Contact
Q 980: Hi- My question is regarding a fountain built of white granite. The iron present in the stone seems to be oxidizing and turning the stone a rust red. Is this treatable, preventable or fixable at all? I believe it’s a chemical reaction between the water, rock and air, but is there a solution to this strange problem? Jessica, USA. May 22 reply
R2: Dear Jessica: Sorry, NOPE. Maurizio, USA, Expert Panelist. Contact
R1: Hi! Not now, It should have been impregnated every 6 months. Pini, USA. Contact
Q 981: I am very interested in rhinestones and I was wondering if you would be able to help me with something like that if yes please contact me. Mohsin, Canada. May 22 reply
A 980: I am trying to find out how the holes were made
in the travertine marble. The type of marble that was used in the building
of the RCA Building in New York. Someone once told me that it was made by worms
traveling thru it. I am now a consultant to a company that is manufacturing
counter tops. I opened up my mouth with this worm statement, that was based on a
40 year old memory. Can you please help.?
Howard, USA. May 5 reply
R1: Dear
Howard: I've heard many whoppers in my days, but this "worm thing" beats them
all hands down!!
Travertine is a
sedimentary rock, mostly made of Calcite (Calcium Carbonate), that was generated
by the deposit of such mineral from hot water springs and streams pouring from
them. The holes are generated either by the gasses trapped by the sediments (the
vast majority), or by water plants that were trapped inside the formation and
then decomposed. Worms?! They must have had some teeth, I'll tell you!!!!
Cordially (don't feel bad, outside of my field I'm the stupidest of them all!!)
Maurizio, USA, Expert Panelist. Contact
A 972: Inform me about study material about 'stone as building material'. Balmukund, USA, April 30. Reply
A 962:
Hi! I was after as much information, such as websites and all, about Carrara
Marble from Italy. Any help would be greatly appreciated! Sincerely,
Christine, Australia, April 19. Reply.
R1: Dear Christine
from downunder: Your question is too wide. I might be able to help you if
you can be a
little be more specific about
what you want to know on the subject of Carrara Marble, that is, if you want
some boring scientific stuff, or more practical information, such as the different
types, what the proper use of it, etc.
Let me know, I can give you both.
Maurizio, USA, Expert Panelist. Contact
Q 929:
I bought granite at an auction and I was told that it is named "black
pearl". I’m now in need of extra pieces but am unable to find the
same in Austin, TX to match my original purchase. Is this an uncommon
granite or is it also known by some other name? Is it also known by
the name of "Imperial black"? I want a piece measuring 6 ft X
4 ft. Tan, USA, April 5. Reply
R1: BLACK PEARL
is granite s.l. from India and marble s.l. from China. IMPERIAL BLACK
is granite s.l. from Australia, also from China, South Africa and Canada and
marble s.l. from USA. Daniel, Slovakia. Contact
Q 926: I am trying to locate about 50-100 sq ft of Classic Oak Arizona
Flagstone. It is to be used for pool coping and needs to be thick
enough to support the tracks for an automatic pool cover. Our contractor
has supplied pieces about 3" thick, but they are severely blemished with black
spots and we need replacement pieces which are not so blemished. If you
have this type of flagstone, can get it, or can suggest some other vendor
who may be able to help, please respond. Our contractor claims to have
been searching for 6 months to get these last pieces! Roy, USA, April 1, Reply
Q 924:
CAN ANYONE HELP ME LOCATE POLY CHROME GRANITE SLAB 3 CM IF AVAILABLE?
THANK YOU, Dennis, USA, March 31, Reply
R1: I do not quite understand your question.
1. POLYCHROME is brown granite from Canada.
2. Polychrome
granites are for instance DAKOTA MAHOGANY - USA, ROYAL MAHOGANY - Sweden,
SAPHIRE BROWN - India, GREEN ROSE - India, GRAN VIOLET - Brasil, FOREST GREEN
- India, ZELENITZA - Ukraine. Daniel, Expert Panelist, Slovakia. Contact
Q 922: I recently bought a brand new apartment which has
marble flooring in the living room. I was told that the marble is from the
Botticino family. All the tiles have what I would call cracks in layman's
terms; in some areas they are quite obvious and in other areas, they are more
minute and "hairline". My question is, are those really cracks or are they
"natural" and inherent in this type of marble? Should I accept the tiles as
they are? Sabrina, Singapore, March 30. Reply
R1: There is not much of a "family" when it comes to "Botticino"
marble. There are three types and three types only of the stuff: "Classico"
(the best); "Semi-Classico" (the second best); "Fiorito" (the third best).
No other marble from this planet can be classified as "from the Botticino
family". All that said, Botticino marble has no obvious cracks, and only a
limited amount of "hairlines" cracks (natural fissures). Usually one has to
go down on hand and knees to see them. Whether you should accept the selection
that you have is not up to me to say
(besides, I don't even know what kind of marble you actually
have). In the stone industry, unfortunately, there is not an official, mandatory
grading (like in the case of lumber), therefore there are no official standards
one can make reference to. Sorry, it's just too bad. Good luck, Maurizio, USA,
Expert Panelist. Contact
A 953: I have a late Permian granite quarry in Australia
producing a fine-grained beige-coloured granite. Because of its unique colour
and uniformity it is in considerable demand world-wide but suffers from a
reaction with stray iron (e.g. drill steels, wedges, saw blades) causing a
patchy to occasionally general yellowing of split and sawn surfaces. It is
not the result of reactive minerals such as sulphide, iron-rich biotite or
fayalite. Because of its moderate porosity (0.25%) it also draws up iron-bearing
fluids by capillary action which results in surficial staining from the bottom
of the block up. The upper surface of blocks, offcuts and slabs are
never discoloured. The granite also becomes locally discoloured by reaction
with alkaline products like expanding cement, alkaline blasting materials
(e.g. ANFO), as well as alkaline mortar. If a 20mm slab is affixed with
dabs of alkaline mortar and the stone is wet these dabs will come out as yellowing
on the front surface within a few days. The yellowing can be easily removed
with Sulphuric acid and further reaction is then minimized. Have you
any suggestions on the reason for this type of reaction or have you come across
this problem before, eg. maybe in Punjab Gold? The granite is
very siliceous (75.2%) Australia, March 29, Reply
e 1485 USA: I am looking for a stone with Mexican or Caribbean origin. It is called shell stone or Durango stone. It looks like a Travertine with fossils. Mar 29 Contact.
A 949: I would like to know the difference between Alabama Red Rock and Crimson Stone. GRFTGirl, USA, March 24. Reply
A 943: Please could you help me with comparing sandstones and limestones with regards to composition and structure. Craig, March 20, USA, Reply
R1: I will keep it simple for you (if you want it more complicated let me know and I will oblige!). Limestone used to be alive. Sandstone did not. Limestone it's a sedimentary rock that derives from the decomposition of (formerly) living organism and, because of that is mostly made of Calcium Carbonate, that classifies it as a calcite rock. Sandstone it's still a sedimentary rock that was formed by layers of sand that, somehow, sunk deep into the belly of Mother Earth. Once there, high temperature partially melted the sand, and high pressure bonded the component together. Since it is of an inorganic origination, it's a silicate rock. Is that good enough for you? Ciao, Maurizio, USA, Expert Panelist. Contact
Q 909: I was told Rojo Alicante was in Group D what does it mean? Does anyone have a reference where I can find the significance of Group A, B, C, or D? Susan, USA, March 17. Reply
R1: Yes, the Spanish Rojo Alicante is a class "D" marble. Marble is classified in groups define by the first 4 letters of the alphabet. Class "A" marble is a marble that is very consistent all throughout its composition, with no natural fissures ("hairline" cracks) or cavities. Class "B" marble is not so consistent and it begins to show minor natural flaws (fissures, tiny cavities). Class "C", "C-D" and "D" are getting worse, of course. Should an "A" marble cost more than a "B", or "C", or "D" marble? Nope! Since Mother Nature charges nothing for all marbles, all marbles start out for free. It's mankind that invented the concept of "price". Price for marble -- like most any other commodities -- is determined by the forces of the market. "Demand and supply" is king! An attractive and scarce "D" marble will cost more than a plentiful but butt-ugly "A" class marble! Lets make no mistake, however. The classification above has nothing to do with what could be defined as a grading of the stone. There is seldom a case where from the same quarry you can get an "A" marble and a lower class one. Is an "A" marble "better" than a "D" marble? If one has to install, say, a marble floor with the "grind-in-place" method, then the A and D do make a difference. In fact, an expert operator will charge more to do a "D" class marble, because, at a certain point of the job, he will have to fill and "stick" all the open fissures and cavities exposed by the first couple of grinding cuts, whereas that extra-work would not be necessary in the case of a class "A" marble. But when all is said and done, at the end of the job, both marbles will be just as "good". It could even turn out that, from a daily maintenance point of view, many a "D" class marble are even better than "A" class marble, and less susceptible to certain types of damages that could be caused by an accident. As far as grading goes, instead, that is better to worst quality within the same stone coming from the same quarry, a few quarriers volunteer some sort of grading. For instance, the Spanish Crema Marfil is graded - by the quarry - as "Residential" and "Commercial" (residential being the better grade). The Greek White Thassos comes in - again by quarry own grading - "Select, "AAA", etc. The Italian White Carrara is graded - again by the quarry – following the A, B, C and D classification. So it's one of the few marbles that can be either "A", or "B" or "C" (to the best of my knowledge, there nothing under the "C" with this type of marble). The fact in the matter is, however, that all this (limited) voluntary grading from a few quarries here and there has very little bearing in real life terms. They are neither official, nor mandatory, and, as such, they have no "teeth" in a court of law. The stone industry World-Wide is unregulated and the consumer is pretty much at the mercy of the dealer, assuming that the dealer itself knows anything about the stone it sells, which is not the case in all too many instances. And everybody's happy! Ciao everybody, Maurizio, USA, Expert Panelist. Contact
A 944: I am interested in using yellow granite from India called YELLOW JUPRANA for a job in Portland Oregon. The design is for a 200' long fountain created by stacking approximately 700 stones that are 4" deep by 30" wide by 48" length stones into various levels. Our design calls for a yellow stone and our budget only allows for yellow granite. My main concern is the stone's reaction to the weather (freeze thaw) and how it reacts to constant water exposure. Is the yellow granite an option for this type of use? Do you have any type of chemical composition reports on the stone or ASTM testing for freeze thaw cycles or erosion? Please let me know if you have any information that will help me to feel comfortable specifying this stone. Raja, March 15, USA, Reply
e 1438
USA: I'm looking for an American quarry which produces black marble, the less
veining the better. Is there a legitimate contender for the title
"The Belgian Black of America"? March 12. Contact.
A 939: One of my friend is doing research in chemistry. He likes to know how many varieties (colors) of marbles are available in India and what are the minerals which gives the color to the marble. Kindly reply. Siva, March 11, India, Reply
R1: Dear Siva, I saw green, black, brown, white, grey,
pink marbles. White color is caused by pure mineral calcite, green (black-green)
color by serpentine (or some amphibole), black and grey by graphite (or
organic
material), yellow to brown color by limonite, red to pink by
hematite. Daniel, Slovakia, Expert panelist. Reply
A 934: How can we find, for example, who carries the Brazilian Verde
Amazonas in this area? (i.e., in the Philadelphia / Wilmington area)
We've visited two of the largest retailer establishments here and haven't
seen the variety you show here; there are several that interest us but we
don't know how to proceed.
Second question: our kitchen plans call for a 12 ft. island / counter
and we favor the slabs with large movement patterns (e.g., J. Colombo) that
would be awkward to piece. Does anyone carry longer slabs such that
one piece could be ordered? (We would need additional granite for counters
other than the island.) USA, March 9, Reply
A 935: I am interested in the Juparano Colombo, which apparently originates in several continents on at least two continents. How can I learn more about the geology of this? Second question: Today, in a marble/granite dealers place, we saw what appeared top be conglomerate. It was already sold and the salesperson did not know its name nor where it came from. He said they had no more and could not get any more. Is there a way of learning through you whether this is available elsewhere? USA, March 9. Reply
Q 900: We are architects and specified slate stools. The Contractor wants to substitute bluestone. It doesn’t sound like a good idea. Any opinions out there? Charles, March 9, USA. Reply
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, Expert Panelist, Reply
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, Expert Panelist, Reply
A 932:
My name is Kate, I am a student at UNSW college of fine arts. I am currently
researching stone.
I am wondering if you could send me, either my
e-mail or the post, any info you might have on the following
specifications:
* Material properties
* structural qualities
*
Characteristics
* Construction methods
* uses and applications
*
fittings and connections
* finishes
* representation of material in
technical documentation
* lists of suppliers and manufacturers
* history
and use of application
* environmental issues
* health and safety
of
course, I am not expecting you to go to too much trouble, any information on any
type of stone would be most appreciated, thanking you in advance for your help.
Kate, Australia, Feb 28, reply
Comments? Complaints? Compliments? aw@findstone.com
The views expressed in this section are not of FindStone.
I find the site to be very helpful. It is impressive the amount of information and number of materials that you have accumulated. Regards, Lynn, USA