Diallage

Diallage is an old 19th century name used to refer to a number of silicate minerals from the amphibole & pyroxene groups.

It is most frequently encountered as a name for hypersthene or diposide, but any gem labelled as diallage would need to be examined carefully to determine it's true constitution.
Further Information
Mineral information:Diallage information at mindat.org
Copyright © Jolyon & Katya Ralph 1993-2021. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.