Wednesday, February 23, 2011

Limestone for Lunch

FYI- The previous post on marble is a direct copy from Wikipedia. Credit where credit is due!

Here is a link to an excellent article on the formation and uses of Limestone from  

One of my favorite bits of trivia: when you open up the foil on a traditional stick of chewing gum, guess what that little bit of white powder is? Calcium carbonate, often in the form of limestone or marble dust. Some stones can be ingested! It is often used as a desiccant or a filler in foodstuffs, toothpaste, or as an inert filler
for tablets and other pharmaceuticals.

It is designated as E170 as a food additive. Ingesting too much can be hazardous, however, so don't start throwing bits of Jerusalem Gold in the blender with your morning smoothy.

Monday, February 14, 2011

What is Marble?

Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, (most commonly limestone or dolomite rock). Metamorphism causes variable recrystallization of the original carbonate mineral grains.
The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals. Primary sedimentary textures and structures of the original carbonate rock (protolith) have typically been modified or destroyed.
Pure white marble is the result of metamorphism of a very pure (silicate-poor) limestone or dolomite protolith. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, iron oxides, or chert which were originally present as grains or layers in the limestone.
Green coloration is often due to serpentine resulting from originally high magnesium limestone or dolostone with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism.

Sunday, February 6, 2011

Harvesting Stone

One of my favorite types of carving marble is Cherokee White. My sculptures Treble Clef and Persia utilize this beautiful stone. It comes from the Polycor Quarry in Tate, Georgia. Here are some pictures of the quarry itself, taken last year. It was a wonderful experience to stand in the hot sun, listen to the wind, and hand pick the boulders that caught my eye. I was struck with the rather poetic notion that I was pulling my own future out of the earth.  You can visit Polycor Georgia Marble at