Inderite is a magnesium borate mineral having composition MgB3O3(OH)5·5H2O. This 10 cm wide sample is from Kern County, California. — Photo: Nessa Eull · CC0
Inderite
A hydrated magnesium borate named for Kazakhstan's Inder lake — described by Soviet mineralogist Boldyreva in 1937.
Intro adapted from Wikipedia (CC BY-SA).
Inderite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula MgB₃O₃(OH)₅·5H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: Mohs hardness 2.5; specific gravity 1.8; typically white or colorless or pink; Vitreous to pearly on cleavages, dull, greasy luster; optically biaxial.
IMA symbol Idr, IMA status: approved, named in 1937.
Relatively rare as a primary mineral in lacustrine borate deposits.
It is found associated with Hydroboracite (Inder deposit, Kazakhstan); kurnakovite (Sarıkaya, Turkey); borax, ulexite, orpiment, realgar (Boron, California, USA).
The name refers to Inder Lake, Kazakhstan, near which the first specimens were collected.
Collections: Collector Favorites, Rare & Remarkable.