Grass green crystal aggregates of the rare mineral cuprorivaite from Cornwall (Wheal Edward, St Just, Cornwall, United Kingdom). It seems that cuprorivaite from this locality is grass green, not blue. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Cuprorivaite
Cuprorivaite is an IMA-recognized mineral species in the silicate class, with the chemical formula CaCuSi₄O₁₀.
It crystallizes in the tetragonal crystal system (space group P4/ncc). It is a member of the Gillespite structural group.
Key properties: Mohs hardness 5; specific gravity 3.08; Vitreous luster; optically uniaxial.
IMA symbol Cuv, IMA status: approved, named in 1938.
Intimately mixed with quartz (Vesuvius, Italy); in a mudstone xenolith ejected from a scoria cone (Sattelberg volcanic cone, Germany).
It is found associated with Quartz.
The name refers to a high copper content and presumed similarity to rivaite.