Calcite Minerals w/Cleavage – Pack of 10
by American Educational Products

A carbonate mineral, calcite is the most stable polymorphic form of calcium carbonite. It has a defining Mohs hardness of 3, and ranges from transparent to opaque. It is typically found as either white or colorless, though impurities can lead to shades of gray, red, orange, blue, green, violet, brown, and black. Its cleavage is usually in three directions, and is parallel to the rhombohedron form.

Calcite is can be commonly found in sedimentary rocks, such as limestone, as well as in metamorphic marble. It is also capable of occurring in vein mineral deposits from hot springs, and has been known to occur in caverns as both stalactites and stalagmites.

It has seen a number of uses over the years. High-grade optical calcite saw use during World War II as the optics for gun and bomb sights, in experiments for a cloak of invisibility, as well as soil remediation and stabilization. In nature, it is a primary component in the shells of marine organisms, and even as the lenses in the compound eyes of the extinct Trilobites.

Each rock or mineral specimen measures approximately 1-2 inches in length along its longest side.

Origin: Mexico