This is a treated matrix opal from the Andamooka opal fields of Australia. These stones are often mined with a white or cream colored matric and are then treated to give them a darker background. The treatment is considered safe and an industry standard and permanent. The appearance of stones like this is a lot like glitter, pressed into black cement.
Size: 39.8mm x 22.5mm x 5.7mm
Weight: 25.6 carats
Ready to ship!
Cheers,
Austin