Kusachiite is a mineral that belongs to the rare sulfate mineral group. It is an incredibly scarce mineral and is primarily found in hydrothermal vein deposits. The name "kusachiite" comes from the Kusu mine in Japan, where it was first discovered.
Chemically, kusachiite is a hydrated sulfate of calcium and copper. Its chemical formula is CaCu6(SO4)2(OH)10·6H2O. Structurally, it crystallizes in the triclinic system and forms prismatic, elongated crystals. Its color generally ranges from pale blue to green or bluish-green, and it possesses a vitreous or pearly luster, depending on the surface.
Kusachiite is known for its wonderful transparency and distinctive color. Its intergrown crystals often form small aggregates, and its cleavage is perfectly distinct. When observed under polarized light, kusachiite exhibits birefringence, meaning it displays different colors as the light passes through, enhancing its visual appeal.
Due to its rarity and limited occurrence, kusachiite has limited practical applications beyond being a collector's mineral or a scientific curiosity. As a result, it holds significant value among mineral enthusiasts and collectors who appreciate its unique properties and aesthetic appeal.
In summary, kusachiite is a stunning and uncommon mineral composed of calcium, copper, sulfate, and water molecules. Its rarity, beautiful color, and transparent crystals make it highly sought after by collectors and mineral enthusiasts alike.
