Information about Cornubite

Cornubite typically appears as bright to dark green crystalline aggregates or encrustations, forming acicular to fibrous crystals in radiating or felt-like masses.

Though rarely well-crystallised, it can also appear in granular or massive habits. Its vivid green colouring makes it visually striking, especially when found alongside other secondary copper minerals such as olivenite or malachite.

Cornubite often forms in oxidised zones of arsenic-rich copper deposits.

Uses and History

Cornubite has no industrial applications, primarily due to its rarity and softness.

However, it may hold value in mineralogical collections and academic research, especially in studying the alteration of primary copper-arsenate minerals.

Specimens are occasionally sought after by collectors for their rich green colour and crystal associations.

Cornubite was first described in 1959 from Wheal Carpenter, Cornwall, from which its name is derived. (“Cornubia” is the Latin name for Cornwall).

Mineralogy

Hazards and Warnings

Toxic mineral: contains arsenic.

Mineral collectors should wash their hands after handling specimens, to avoid any exposure to potential toxins.

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Further Reading / External Links

• https://www.mindat.org/min-1132.html
• https://en.wikipedia.org/wiki/Cornubite
• https://webmineral.com/data/Cornubite.shtml
• https://handbookofmineralogy.org/pdfs/cornubite.pdf