Opal (mineral)
Specimens of opal, a mineral composed of silica, but whose water content is usually between 3 and 9%, and it can even reach 20% depending on the variety. Here many collector’s items are presented with a description, one or more photos and sometimes a video. These opals are for sale.
It is hydrated silica, with the chemical formula SiO₂ – n H₂O. Opal-AG, the common opal, is formed of microspheres of amorphous silica, associated with molecules of water in variable proportions, trigonal crystalline system of quartz for Opal-AN (the hyalite) and for Opal-CT (the lussatite) is composed it of cristobalite-tridymite.
It is not a mineral species in the strict sense of the term, but this family has official recognition by the IMA.
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VENDU
Opale Ménilite, Ménilmontant district, Paris, Ex-Doumet.
90,00€ Read more -
Opale CT, Sarthe, Ex-Doumet.
80,00€ Add to cart -
Opalized gastropod, Coober Pedy, Australia.
345,00€ Add to cart -
Blue CT opal, Opal Butte, Oregon, USA (United States).
40,00€ Add to cart -
VENDU
Blue Opal CT, Opal Butte, Oregon, USA (United States).
40,00€ Read more -
Opale, Opal Butte, Oregon, USA (United States).
65,00€ Add to cart -
Opale, Opal Butte, Oregon, USA (United States).
50,00€ Add to cart -
Quincyte (Opale), Quincy, Cher.
180,00€ Add to cart -
Hyalite opal, Valec, Bohemia. Czech Republic.
85,00€ Add to cart -
Eisenopal (Opale), Kraubath, Steiermark (Styria), Austria.
35,00€ Add to cart -
Opal and Uranophane, Margnac I mine, Haute-Vienne, Limousin.
200,00€ Add to cart -
Opale, Opal Butte, Oregon, USA (United States).
40,00€ Add to cart -
Hyalit (Opal Hyalite), Ex-Musée-Bally.
30,00€ Add to cart -
VENDU
Forcherite opal, Schöninger (Klet), Bohemia, Czech Republic.
45,00€ Read more -
VENDU
Quincyte (Opale), Quincy, Cher.
85,00€ Read more -
VENDU
Opale Menilite, Ménilmontant, Paris.
40,00€ Read more -
VENDU
Kascholong Opal (Opal), Huttenberg, Kärnthen, Austria.
30,00€ Read more