Réf : BK910
2 Polished Noble Opals - Australia - Polished Minerals 0.6 cm / 0.15 g / BK910
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OPAL belongs to the silicate group. It contains mainly silicon and a certain amount of water. Its chemical formula is SiO 2 .nH 2 O.
It is a valuable mineral variety.
OPAL occurs in the form of massive silica and water spheres with magnificent reflections. Iron and manganese oxides give it its yellow, red, and black colors. The hardness of Opal varies between 5 and 6/10 on the Mohs scale (10 for diamond) and its density varies from 1.9 to 2.3 (1 for water). The line on porcelain is white.
DOUBLET OPAL is a thin slice of Opal glued onto a black background, usually glass, to make the colors shine more dynamically like real black Opals.
BOULDER OPAL is an association of Opal included in iron ore and polished.
The name Opal comes from the Indian upala which means precious stone .
Unique piece - Contractual photos
Origin: Australia, polished minerals
Dimensions: 0.6 x 0.4 x 0.3 cm
Weight: 0.15 g
