Chemical Formula Cu2H2Si2O5(OH)4
Color Blue, Green, Multicolored
Hardness 2 – 4
Crystal System Orthorhombic
Refractive Index 1.4 – 1.6
SG 2.0 – 2.2
Double Refraction None
Luster Vitreous to greasy
Mineral Class Chrysocolla
Chrysocolla gemstones may be solid in color, but are more often multicolored blue and green, with interesting color patterns or mottling. Brown and black specks are often also admixed. Due to its color similarity to Turquoise, Chrysocolla can be used as a cheaper substitute and is occasionally falsely labelled as Turquoise.
A gem variety of Chrysocolla known as Eilat Stone is a greenish-blue mixture of Chrysocolla, Turquoise and other copper minerals such as Malachite from the ancient copper mines north of Eilat, in the southern Israel. Much of the material sold as Eilat Stone is in fact not really from Eilat but originates in other localities and is falsely labelled.
Chrysocolla is used as a minor opaque gemstone as well as a collectors gemstone. It is cut into cabochons and beads and only occasionally into other gemstone cuts.
Eilat Stone – Greenish-blue mixture of Chrysocolla, Turquoise and other copper minerals such as Malachite from the copper mines near Eilat, Israel.
Chrysocolla TREATMENTS AND ENHANCEMENTS
Chrysocolla is natural and not treated or enhanced.
Chrysocolla is found worldwide, though significant sources include the Congo (Zaire), Israel, Australia, Peru, Chile, Mexico, and in the U.S. in Arizona.
Turquoise and blue Chalcedony are harder, and Variscite is usually greener without any blue hue.