Information
AUSTRALIA OPAL CO.
Australian opal mining company founded in 2003.
Australia Opal Co is based in Sydney, we manufacture and wholesale Black and Boulder opal, and export to Europe.
Opal
Solid natural hydrogel, amorphous silica SiO2 · nH2O (hydrate of silica).
The name supposedly comes from the Latin "oralus" or Sanskrit "upala", which means "precious stone".
Transparency in varying degrees. Amorphous.
The hardness of 5-6.5 and a density of 1,9-2,3 g/cm3.
Application
Jewelry and collector stone - in jewelry are mainly the so-called precious opal with iridescent play of color, with opalescence.
Opals are divided into:
Noble - (opalescent);
ordinary - (no opalescence).
Precious opal
Precious opal - a special variety of the mineral, characterized not only extremely beautiful multicolored rainbow game inside it, but also quite stable over time as the color stability of the game and the stone (other varieties of opal eventually become turbid and crack, losing water.) Black Opal in contrast to its "fire" colleagues appreciate, popular, and very expensive. Belongs to the precious opal gemstones, the best examples are very much expensive. The richest collection of precious opals owned Imperial Vienna mineralogical study. Most precious opals are mined in Australia. Also in Mexico - "fire", but due to the fragility, almost not used.
Common Opal
Common opal - no play of colors, without opalescence. Transparency in varying degrees. Sometimes colorless but for the most part, painted in a variety of soft colors. Beautiful samples are ground and are considered semi-precious stones.
In Australia
Opal is found on every continent, but in the field in Australia for about 97% of world production. 90% is called "light opal 'or white kristalichskimi opals. Most opals are mined in Coober Pedy in South Australia. Ordinary and fire opals are often found in Mexico. Other Australian town, Lightning Ridge in New South Wales, the black opal is mined in Lightning Ridge is 95% of the world's famous black opal with dominant black color (with a play of colors from dark gray to black and blue).
Rating Opals
Estimate of its value is on the same criteria as for the diamond: color, clarity, and Carat form. Red is the most expensive, followed by orange, green, blue and purple, but the determining factor is the brightness of the opal.