The OPAL, particularly engaging stone, and extremely varied.
IT is regrettable that its industry ignores numerous legends linked to this gem, and that a textbook on its classification, been not until now established.
The varieties of the opal are numerous.
Firstly, it is necessary to define this stone, the OPAL is a hydrated frost of silica coming in form of small spheres centro - removed supported groups by a siliceous hydrated cement, in general the precious opal contains, between 6 and 10 % of water.
DIFFERENT TYPES Of OPALS
The varieties of Opals accepted various Names according to their Aspects
* Opal Harlequin * it is an Opal, in the regular chromatic drawings resembling a mosaic in the form of angled, rounded up stain or ensconced (numerous motives harlequins).
* White opal *Opal which the colour of the bottom is white milky or light grey (ligtht opal - white opal) the games of colours are soft and nice.
* Opal crystal *Opal of a big translucence, giving bright one games of colours.
* Opal dendritique-bubbles * Common Opal with dendrites of very soft colour.
* Opal of water or hyalite, water Opal, jelly Opal, Claro-o-translusante*Variété of very clear Opal and a big transparence, bets on a black bottom, lively and fleeting coloured fires appear.
* Opal girasol * Almost uncolored and transparent Opal with bluish images.
“Opal hydrophane”Once saturated with water, this opal shows made iridescent colours then.
The Name of the opal, comes from a Sanskrit term, "UPALA" which means "Precious stone"
THE VALUE OF OUR OPALS, IS CALIBRATED TO A CRITERION OF QUALITY DEFINED BY The AUSTRALIAN ASSOCIATION OF GEMMOLOGIE, WHICH PUT IN THE POINT A MODE OF DETERMINATION AND UNIQUE CLASSIFICATION, EVERY OPAL IS DETERMINED ACCORDING TO COLOURS AND ACCORDING ARCHITECTURE OF THE DRAWINGS WHICH DETERMINES ITS CATEGORY, TO A LADDER OF CLASSIFICATION, ITS VALUE, ITS CURIOSITY, AND ITS CATEGORIE.
(Text de Géo-concept, Géologue)