Stibiconite ps. Stibnite, with Calcite

Item Description

This is a classic from Mexico: a large, 8.4 cm crystal of Stibnite (antimony sulfide) that has been pseudomorphed by Stibiconite (antimony oxide hydroxide), where the sulfur atoms having been lost in the process. This is not a surface replacement or coating, but a true pseudomorph in which the crystal is Stibiconite clear through, retaining the exact form of the former Stibnite, both sharp surfaces as well as contacted surfaces and ridges. Formerly in the collection of John Parnau and then stibnite specialist Bob Byers.