Epsomite

Official mineral name for magnesium sulfate, also called Epsom salt or bittersalt. Epsomite is named after a bittersalt spring near Epsom in Surrey, England. In…

Chrysopal

Green nickel-bearing variety of opal. So named for the similarity between chrysopal and chrysoprase, a nickel-bearing variety of chalcedony. Also known by the longer-standing name…

Endurite

Denoted as an “unusual gemstone” from India. It contains alternating layers of red jasper and silver-gray hematite. That sounds like banded iron stone, also known…