Many
of you reading this may think you know your marble types. Anyone who
has been in the stone industry for a while should be able to tell
marble from granite and limestone, right?
Well
take the following test and see how much you really know. MARBLE,
GRANITE OR LIMESTONE? Each one of the following stones are either
marble, granite or limestone. Place and M for Marble a G for Granite
or an L for Limestone next to each line to identify where it fits.
NEGRO
MARQUINA _____
ROJO ALICANTE _____
BIANCO CARRARA_____
TRAVERTINE CLASSICO_____
CREMA MARFIL_____
EMPERADOR_____
CHANDORE_____
JERUSALEM STONE_____
ROSATTA_____
How many of the above did you classify as marble?
You may be surprised to discover that only one of the above materials
is true marble (see answers ar the end of article). The rest are
all limestone, except for Ubatuba, which is a granite.
Many
of the materials that we deal with everyday in the stone industry
are often mistaken for marble. How many times have you heard someone
talk about travertine marble? Why the confusion? To understand the
confusion we need to take a close look at the common term "marble"
and the geological term "marble".
The history of the word "Marble" is interesting and can
explain why it is misused today. "Marble"was derived from
the French word "Marbre" which was derived from the Latin
word "Marmor". "Marmor" was derived from the
Greek word "Marmaros". "Marmaros" is defined
as a glittering or sparkling stone. Several other Greek words contribute
to the word "Marmaros".
"Marnantai" relates to the crushing and deformation forces
of nature as reflected on the surface of certain stone. Now lets
take a look at Mr. Webster's definition of marble, which states
the following:
1.a: limestone that is more or less crystallized by metamorphism,
that ranges from granular to compact in texture, that is capable
of taking a high polish, and that is used especially in architecture
and sculpture.
1.b: something (as a piece of sculpture) composed of or made from
marble.
1.c: something suggesting marble (as in hardness, coldness, or smoothness).
Basically any stone that will take a polish can be called "marble".
Now you can see how this gets confusing. Now let's look at "Marble"
from a geological point of view.
Geologists are very clear in defining marble. A rock primarily composed
of calcite or dolomite and whose structure has been altered by specific
geological forces is considered marble.
To confuse the issue even further The American Society for Testing
Materials (ASTM) defines marble as a crystalline rock capable of
taking a polish and composed predominantly of one or more of the
following minerals: calcite, dolomite, or serpentine.
ASTM also considers travertine a marble. Travertine is a sedimentary
rock and is a limestone, not a marble. An argument can be made that
many of these limestones are commercially called marble. That's
fine, but now you know the real story.
Fred Hueston,
Technical Editor, Stone Magazine
Ashlee Publishing
18 E. 41st St., New York, NY 10017
Answers:
NEGRO MARQUINA __L__
ROJO ALICANTE __L__
BIANCO CARRARA __M__
TRAVERTINE CLASSICO __L__
CREMA MARFIL __L__
EMPERADOR __L__
CHANDORE _L__
JERUSALEM STONE __L__
ROSATTA __L__
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