Home > Burmese Minerals – May 22 > MS1340 Pyrite altering to Goethite
Pyrite altering to Goethite - Sold
- Mogok Stone Tract
- Mandalay Region
- Burma
- 2.5 by 2.1 by 1.4 cm – Thumbnail specimen (fits into a 2.5 cm cube)
Pyrite forms brassy color crystals, chemically iron disulfide. On the surface of the Earth, the Fe2+ ions in pyrite are not entirely stable, with the action of water, they alter to Fe3+. This explains why goethite (or other iron minerals) commonly alters from pyrite. This specimen is a cluster of dominantly cubic crystals, with pyritohedral modications to 12 mm. A floater specimen. Some of the crystals show indentations where other crystals grew into the cluster.
