Opal (rough and cut set), Acari Mine, Caraveli Province, Arequipa Department, Peru, thumbnail, 3.2 x 3.2 x 2.8 cm (Crystal), 12.71 ct (Gem), 3.2 x 3.2 x 2.8 cm (Specimen); 12.71 carats; 19.26 mm x 14.70 mm (Gem) - This is some of the most well known Opal to hit to market, mostly because of its notable blue color., For sale from The Arkenstone, www.iRocks.com. For more details on this piece and others, visit https://www.irocks.com/minerals/specimen/43159