A light blue copper corrosion product that rarely occurs as a mineral. As a mineral, it was discovered in 1963 at the Centennial Miner near Calumet, Michigan. Calumetite has been identified as a copper corrosion product on bronzes (Scott 2000).
Physical and Chemical Properties
- Composition = Cu(OH, Cl)2 - 2(H2O)
- Description = azure to light blue crystals (orthorhombic)
- Streak = bluish-white
- Luster = pearly
- Hardness = 2
Resources and Citations
- David Scott, 'A Review of Copper Chlorides and Related Salts in Bronze Corrosion and as Painting Pigments'. Studies in Conservation, 45, 39-54, (2000).
- WebMineral: Calumentite
- Wikipedia: Calumentite
- Mindat: Calumentite