Information about Clinohumite

Clinohumite is a member of the humite group – a series of magnesium silicate minerals that also includes norbergite, chondrodite, and humite – and the one most likely to occur as gem-quality transparent crystals.

As a collector and gem mineral, clinohumite is most prized in its orange to golden-yellow transparent gem-quality form from the Pamir Mountains of Tajikistan, which produces crystals of remarkable clarity and colour – among the finest gem-quality specimens of the species in the world.

It also occurs in marble contact zones, where it typically forms brown to amber-coloured granular masses rather than distinct crystals. A rare titanium-bearing variety (Ti-clinohumite) from the Pamir district and from Val Malenco in Italy shows a particularly intense golden-orange colour due to titanium substitution.

Uses and History

Clinohumite was named in 1876 by Alfred Lewis Oliver Legrand Des Cloizeaux, from its type locality at Mount Somma, near Naples, Italy. The clino- prefix reflects the monoclinic symmetry of this particular member.

The finest gem-quality clinohumite comes from the Pamirsky Mine in the Pamir Mountains of Tajikistan, which has produced vividly coloured transparent orange and yellow crystals of gem quality used in jewellery and avidly sought by collectors.

Additional gem-quality material has come from the Taymyr district of Siberia, Russia. Pale yellowish-brown to amber examples occur in marble contact aureoles worldwide, including in Italy, Sweden, and various alpine localities.

Transparent clinohumite is occasionally faceted as a gemstone, though its limited production, relative softness (compared to conventional gems), and imperfect cleavage mean it remains a specialist collector stone rather than a mainstream gem. Its vivid colour, high refractive index, and rarity make it desirable among gem collectors.

Mineralogy

Hazards and Warnings

No specific hazards are associated with clinohumite under normal handling conditions. Standard dust precautions apply when cutting or polishing.

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.

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