Blue, Bluish-Green, and Green...

Mineral Matters #386

This week’s Facebook Mineral of the Week Group’s selected theme is the minerals linarite, caledonite and brochantite. They are all beautiful secondary sulphate minerals formed by the oxidation of copper sulphide minerals and are often found together.

Linarite occurs as deep azure blue prismatic crystals that can be translucent or transparent.

Caledonite occurs as pale blue to greenish blue elongated crystals that are usually transparent.

Brochantite occurs as emerald green to dark green to bluish-green prismatic or acicular crystals, that may be striated, and can sometimes be hard to distinguish from malachite.

Below: Linarite with white hemimorphite, Silver Gill Mine, Caldbeck Fells, Cumbria, England, UK. Width of view 5.75mm.

Below: Caledonite, Red Gill Mine, Caldbeck Fells, Cumbria, England, UK. Width of view 5mm.

Below: Brochantite, California Mine, Copiapo, Atacama, Chile. Width of view 15mm.