Myerhofferite after Inyoite

This is a somewhat uncommon alteration mineral collected by Ken in 1975. According to Moore (Compendium of Mineral Discoveries), these pseudo crystals seldom exceeded 2.5cm for the more aesthetic specimens. There are two examples in this collection, a thumbnail and  this 13cm piece. Crystals on this specimen reach a bit over 3cm! Expect the matrix to be a bit crumbly. Rarely found in the market today. Ex Ken Roberts collection.

Locality: Corkscrew Mine, Blanco District, Inyo County California

Composition: Hydrated borate mineral of calcium  Ca₂B₆O₆(OH)₁₀·2H₂O, CaB₃O₃(OH)₅·H₂O or Ca₂(H₃B₃O₇)₂·4H₂O