Glaucodot

Glaucodot is a cobalt iron arsenic sulfide mineral with formula: (Co,Fe)AsS. The cobalt:iron(II) ratio is typically 3:1 with minor nickel substituting. It forms a series with arsenopyrite (FeAsS). It is an opaque grey to tin-white typically found as massive forms without external crystal form. It crystallizes in the orthorhombic system. The locality at Vastmanland, Sweden has rare twinned dipyramidal crystals. It is brittle with a Mohs hardness of 5 and a specific gravity of 5.95. It occurs in high temperature hydrothermal deposits with pyrrhotite and chalcopyrite. Glaucodot is classed as a sulfide in the arsenopyrite löllingite group.

Additional recommended knowledge

Essential Laboratory Skills Guide

How to ensure accurate weighing results every day?

Daily Visual Balance Check

Glaucodot was first described in 1849 in Huasco, Valparaíso Province, Chile.

References

• Webmineral
• Mindat with location data
• Scandinavian mineral gallery
• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., p. 288, ISBN 0-471-80580-7