This natural Multicolor Black Opal originates from Ethiopia and its weight is about 5 carats. The measurements are 15.22mm x 9.69mm x 6.08mm (length x width x depth). The shape/cut-style of this Black Opal is Cushion Cabochon. This 4.89ct Black Opal gem is available to order and can be shipped anywhere in the world.
Smoke treatment is a relatively old method of stone treatment that has just recently been reinvented. The process involves wrapping opals into silver foil strips and slowly heating them, allowing the buildup of smoke inside the foil. Carbon formed by the smoke, penetrates deep into the opal stone and stains the original color with deeper and darker tones. Smoke treatment is intended to give the opal brighter play of color, because the bright colors contrast better on darker backgrounds. More about treatments
About Black Opal
Black Opal is considered the most valuable of opal varieties. Black Opal contains traces of iron oxide and carbon elements not found in other common opals. These combined elements give black opal the unique color properties it is famed for. Black Opal is mainly found in Lightning Ridge of NSW, Australia. In 2008, New South Wales declared Black Opal as its Official State Gemstone.
Ethiopia is also known to produce treated black opal. The Ethiopian black opal is treated with a smoking process that darkens the color of the opal. The treatment enhances the play of color, rivaling some of Lightning Ridge’s opals. The treated Ethiopian Black Opal is a great value because it sells for much less than Australian Black Opal.