Minerals
Keystoneite
keystoneite
Mg0.5NiFe³⁺(Te⁴⁺O3)3·4.5H2O
Keystoneite: Mineral information, data and localities. — via www.mindat.org · Source
Overview
Keystoneite is a naturally occurring tellurite mineral. It was discovered in 1988 at Keystone mine, Colorado, the type locality for which it is named. It is the Ni2+ analogue of zemannite.