Dianne McCormick, age 12, of Visa a, Ca for her question:

What is marble made from?

Marble is made from sea shells, tiny shells which lived in oceans of long., long ago. Little sea dwellers, some of them no bigger than pin heads, made these shells from calcium carbonate. They lived and died in countless numbers through countless generations. Their empty shells sifted and sank through the water and built up piles and layers on the floor of the sea.

Perhaps the piles of shells were then covered with mud and perhaps the sea became dry land. The layers became pressed into limestone. Maybe other adventures followed. The limestone 1ayers became buried deep under heat and pressure. If conditions were right, the hard limestone became still harder marble. Pure marble is a white mineral made mostly of calcium carbonate from ancient sea shells. Marble is colored by impurities and there era marbles for all the colors of the rainbow. In the United States alone, 120 different kinds of marble are quarried.