Rock & Mineral Kits: Get a rock, mineral, or fossil kit to learn more about Earth materials. Crushed marble is also used to reduce the acid content of soils, the acid levels of streams, and as an acid-neutralizing material in the chemical industry. Highest purity marble is often crushed to a powder, processed to remove impurities, and then used to make products such as Tums and Alka-Seltzer that are used for the treatment of acid indigestion. That makes it very effective at neutralizing acids. The specimen is about two inches (five centimeters) across.Ĭalcium carbonate medicines: Marble is composed of calcium carbonate. Gray Marble: This specimen has calcite cleavage faces up to several millimeters in size that are reflecting light. Some might contribute to the formation of gem minerals such as corundum - the mineral of ruby and sapphire. The crystals usually grow in size and as the level of metamorphism progresses.Ĭlay minerals within the marble will alter to micas and more complex silicate structures as the level of metamorphism increases. Metamorphism will have very small calcite crystals. Marble that has been exposed to low levels of Recrystallization is what marks the separation between limestone and marble. It also occurs without formingįoliation, which normally is found in rocks that are altered by the directed pressure of a convergent plate boundary. Recrystallization obscures the original fossils and sedimentary structures of the limestone. Specimen, they might only be recognized as a sugary sparkle of light reflecting from their tiny cleavage faces when the rock is played in the light.Īs metamorphism progresses, the crystals grow larger and become easily recognizable as interlocking crystals of calcite. In the early stages of the limestone-to-marble transformation, the calcite crystals in the rock are very small. This process also occurs at convergent plate boundariesīefore metamorphism, the calcite in the limestone is often in the form of lithified fossil material and biological debris.ĭuring metamorphism, this calcite recrystallizes and the texture of the rock changes.

Some marble also forms by contact metamorphism when a hot magma body heats adjacent limestone or dolostone. The transformation of limestone into marble usually occurs at convergent plate boundaries where large areas of Earth's crust are exposed to the heat and pressure of regional metamorphism.

When u lose your marbles