Chrysocolla in Quartz Semi-Polished Half Sphere - 75mm, 267g
Locality - Congo Size – 75 x 69 x 43mm Weight – 267g
This unique chrysocolla in quartz semi-polished half sphere displays nice teal blue chrysocolla veins running through a milky quartz matrix. It has been nicely polished across its bow-fronted display face to a high lustre, whilst the back and base of the piece has been left naturally rough. This unusual material is often marketed inaccurately as 'ajoite' in quartz, though ajoite only appears as zoned phantoms in the tips of natural quartz crystals, never in massive form or as opaque inclusions.
Chrysocolla is a hydrous copper silicate – a member of a small group of copper-bearing gems that includes malachite, azurite, larimar, sunstone, tourmaline and turquoise - typically found as glassy botryoidal or rounded masses or bubbly crusts, jackstraw mats of tiny acicular crystals or tufts of fibrous crystals. The name was first used by Theophrastus in 315 B.C. and comes from the Greek chrysos, meaning "gold," and kolla, meaning "glue," referring to its use as a flux in soldering gold. Pure chrysocolla is opaque and is found in various shades of blue and green. It is often found with traces of copper, iron and manganese oxide, or mixed with other secondary copper minerals such as malachite, azurite, turquoise, opal or quartz. On its own, chrysocolla is very soft and fragile (with a hardness of only 2), but when mixed with these other minerals becomes harder (at 6.5 – 7), more durable and also shows unique patterns in a wide range of colours. Deposits are found in Chile, Israel, Mexico, Peru, Russia, Nevada and D.R. Congo.