CHRYSOCOLLA

The name Chrysocolla was first used by Theophrastus in 315 B.C. and comes from the Greek “chrysos”, meaning “gold,” and “kolla”, meaning “glue,” in allusion to the name of the material used to solder gold. André-Jean-François-Marie Brochant de Villiers revived the name in 1808.

It displays beautiful shades of blue and green, sometimes with brown and red tones when mixed with other minerals like jasper or malachite.

Texture: It can appear as a hardened silica gel, rather than a typical mineral, and is often found mixed with chalcedony, quartz, or turquoise.

Formation: It occurs as crusts, rounded masses, or vein fillings, rather than forming in distinct crystals.

Origin: It forms in the oxidation zones of copper deposits, encrusting or replacing other secondary minerals.

Is it a crystal? It is not technically a true crystal, it’s a secondary mineral that typically forms in botryoidal, rounded, or crust-like masses, rather than with distinct crystalline structures. While it’s sometimes called a “blue-green crystal” in the gemstone trade, any apparent crystals are usually “pseudomorphs” (meaning the mineral has taken on the shape of another mineral that has since dissolved away). 

USES

Jewelry: Chrysocolla’s beautiful blue-green color makes it a popular gemstone for jewelry, often cut into cabochons or used as beads in necklaces and bracelets.

Art and Cosmetics: Historically, it was ground and used as a blue pigment in paint, on frescoes, and even as eyeshadow.

Copper Ore: As a copper-bearing ore, chrysocolla is used in metallurgical processes to recover copper.

MOHS HARDNESS

It has a variable hardness on the Mohs scale. Pure chrysocolla is relatively soft, ranging from 2 to 4, making it prone to scratching. When mixed with quartz or Chalcedony, it can be durable enough for jewelry, with a hardness reaching up to 7.

LUSTER

Vitreous, Waxy, Earthy

CHEMICAL COMPOUND

Formula: Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1
Colour: Green, bluish green, blue, blackish blue to black, or brown and rarely yellow

WHERE TO FIND

• Southwestern USA (especially Arizona)
• Chile
• Australia
• France
• Democratic Republic of the Congo

DIAGNOSTIC PROPERTIES

The main diagnostic properties are its distinct blue-green color, its variable and relatively low hardness, a light green or white streak, and a lack of cleavage. Because it is a secondary copper mineral, it is often found alongside other copper-bearing minerals like malachite, azurite, and quartz.