AUSTRALIAN Black Opal Clasp Southwest Design Sterling Silver 6x10mm

This is a stunning Andamooka Australian Black Opal with green and blue fire, measuring 6x10mm and set in our own .925 sterling silver clasp. The overall size is approximately 28x11mm, the perfect finish for your necklace or bracelet design! It is called "concrete Opal" because it resembled concrete with small specks of opal among the grains prior to a unique process to elevate the sparkle. It is a porous quartzite host rock in which water has turned to opal, deposited among the quartz grains millions of years ago.