What is Eskolaite?
Eskolaite is the chromium oxide mineral, usually dark green to black and associated with chromium-rich metamorphic rocks and ore assemblages.
Mineralogy and structure
Reference formula: Cr2O3. Eskolaite is trigonal and structurally related to corundum and hematite. It is hard and dense but commonly fine-grained rather than forming large gem crystals.
Colour and appearance
Typical colours include dark green, black, green-black. The usual granular, massive, platy habit and sub-metallic, metallic lustre are useful descriptive features, but colour alone is not diagnostic.
Formation and localities
Eskolaite forms in or is associated with chromium-rich metamorphic rocks, chromite deposits and high-temperature contact environments. Important documented localities include Finland, Russia, Turkey, South Africa and the United States.
Collecting and care
Durable for display; avoid confusing dark massive material with chromite without analytical or locality evidence.
Eskolaite in popular symbolism
Modern crystal guides sometimes associate Eskolaite with symbolic themes based on colour or collecting tradition. These associations are cultural interpretations, not mineralogical or medical properties.
