Aragonite & Kutnohorite Crystal Geode Half - Italy

This is a breathtaking geode half containing microscopic aragonite crystals, as well as rare kutnohorite spheres. The translucent, elongated crystals are aragonite and can be found coating the entire interior of this geode. The small dark spheres are kutnaohorite, a rare calcium manganese carbonate mineral with the chemical formula Ca(Mn,Mg,Fe)(CO3)2.

The crystals are best viewed in detail, under a microscope. The cavity of this small geode is about .6" wide.

Aragonite is a carbonate mineral, one of the two commonly occurring crystal forms of calcium carbonate, the other form being calcite. It is formed by biological and physical processes, including precipitation from marine and freshwater environments. It's crystal lattice differs from calcite, resulting in a different crystal shape. Aragonite forms naturally in most mollusk shells, and as the calcareous endoskeleton most corals.
Aragonite & Kutnohorite
Levane, Arezzo Province, Tuscany, Italy
1.1" wide