What is Chrysocolla?
Chrysocolla is a gemstone with a beautiful sky blue to bluish-green colour. Copper in its chemical structure is responsible for the bright attractive colour. It is often multicoloured with inclusions or veining of black and brown matrix material. Chrysocolla's lack of widespread gem use is due to its low hardness and lack of durability. It is sometimes coated or admixed with harder Quartz, and these harder, more solid forms are better fit for gemstone use.
Name and discovery
The name comes from the Ancient Greek, "gold glue", in allusion to the name of the material used to solder gold, and was first used by Theophrastus in 315 BCE.
Formation and occurrence
It is of secondary origin and forms in the oxidation zones of copper ore bodies. Associated minerals are quartz, limonite, azurite, malachite, cuprite, and other secondary copper minerals.
It is typically found as botryoidal or rounded masses and crusts, or vein fillings. Because of its light colour, it is sometimes confused with turquoise.
Notable occurrences include Bacan Island Indonesia, Israel, Democratic Republic of Congo, Chile, Cornwall in England, and Arizona, Utah, Idaho, New Mexico, Michigan, and Pennsylvania in the United States.
Chrysocolla Gemstone Properties
| Chemical Formula | Cu2H2Si2O5(OH)4 |
| Colour | Blue, Green, Multicolored |
| Hardness | 2 - 4 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.4 - 1.6 |
| SG | 2.0 - 2.2 |
| Transparency | Opaque |
| Double Refraction | None |
| Luster | Vitreous to greasy |
| Cleavage | None |
| Mineral Class | Chrysocolla |