4.7" Tricolor Calcite - Mexico

This is a rough, unpolished chunk of tricolor calcite from Mexico.

Size (Inch): 4.7x2.75x3.45

Rainbow calcite, also known as tricolor or banded calcite, is a distinct geological formation of calcium carbonate (CaCO_3) characterized by its vibrant, parallel color bands. These striking layers—most commonly featuring alternating ribbons of amber-orange, creamy white, and deep forest green or red—are the result of fluctuating mineral impurities, such as iron, manganese, or organic matter, that settled sequentially during the stone's sedimentary deposition over thousands of years. As a member of the trigonal crystal system with a low Mohs hardness of 3, this massive variety of calcite possesses a characteristic waxy to vitreous luster and noticeable translucency, making it a valuable specimen for studying sedimentary mineral growth and a popular material for ornamental lapidary arts.