Chrysocolla

chrysocolla
Rough chrysocolla

Chrysocolla is a sky blue, blue green, green colored hydrated copper silicate mineral with traces of oxides of copper, iron and manganese and occurs as a compact, grape-like groups.

The general structure of chrysocolla is botryoidal. It is associated with malachite, turquoise, jasper and quartz. Crystals intergrown with quartz or with opal are more commonly used in jewellery. Chrysocolla intergrown with malachite and turquoise is known as eilat stone which originated from King Solomon’s mines.

Eilat stone is the best simulant for turquoise and sometimes can not be differentiated easily by visual observation. Chrysocolla mixed with jasper is known as parrot-wing which is of course very rare and sought by many jewelers. Chrysocolla mixed with quartz is known as stellarite which is pale blue in color.

Chrysocolla along with eilat stone, parrot wing and stellarite is extensively used in jewelries as beads, rings, ear rings, pendants, lockets, bracelets etc.

Chrysocolla Pictures

Rough chrysocolla Chrysocolla rock

Cause of Color :

Color varies with the impurity present. The blue color is due to the presence of copper.

Chemical Composition :

Hydrated Copper Silicate – CuSiO3.2H2O

Crystal System / Forms :

Crypto-crystalline aggregates with an enamel like texture.

Cuts & Uses :

Cabochon, beads, carvings, etc.

Dispersion : None.
Hardness : 2 - 4; increases to 7 with more quartz mixtures.
Lustre : Greasy to vitreous.
Magnification :

Aggregate surface texture. Botryoidal.

Optic Character :

Anisotropic (D.R.); Uniaxial positive / A.G.G.

Pleochroism : None.
Refractive Index / Birefringence :

1.50 (mean R.I.)

Simulants (with separation tests) :

Turquoise (R.I., S.G., spectrum, structure)

Sources :

U.S.A. (New Mexico), Russia, Chile, Peru and Zaire.

Specific Tests :
  • Turns yellow with hydrochloric acid.
  • Eilat stone: Chrysocolla mixed with malachite and turquoise.
  • Parrot-wing: Chrysocolla mixed with jasper (brownish-green).
  • Stellarite: Chrysocolla mixed with quartz has higher properties (light blue).
Spectrum :

Not characteristic.

Synthesis :

None.

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