Gemmology
English | Български
Where am I? > Home > Repository > Opal


Gallery view selector

Colour selector
Simple colour schemeredorangey redreddish orangeorangeorangey yellowyellowgreenish yellowyellowish greenslightly yellowish greengreenvery slightly bluish greenbluish greenvery strongly bluish greengreen-blue or blue-greenvery strongly greenish bluevery slightly greenish bluebluevioletish bluebluish violetvioletbluish purplepurplereddish purplestrongly purplish redslightly purplish redcolourlessgreyblack

Opal — specimens [gallery view] (Page 2)


Regarded as mineral species for historical reasons; not a true mineral in the accepted sense of the word as it is either composed of cristobalite and/or tridymite or of amorphous silica; sedimentary and secondary from the alteration of high silica igneous extrusive rocks. There are specimens of 2610 carats (Arem, 1987: 139).
Opal — specimen 0461
0461
Madagascar
Opal — specimen 0469
0469
Ethiopia
Opal — specimen 0518
0518
Madagascar
Opal — specimen 0713
0713
Ethiopia
Opal — specimen 0720
0720
Ethiopia
Opal — specimen 0373
0373
Madagascar
Opal — specimen 0557
0557
Madagascar
Opal — specimen 0361
0361
Madagascar
Opal — specimen 0073
0073
Madagascar
Opal — specimen 0176
0176
Madagascar

Opal — specimens — 40
First Previous Page 2 of 4 Next Last