Matrix Opal with Extensive Red Fire - Andamooka, South AustraliaLike most matrix opal material from

Matrix Opal with Extensive Red Fire - Andamooka, South AustraliaLike most matrix opal material from this region this specimen was sugar treated by the miners before being honed to a superb level of polish. The process—a classic and long-standing tradition—involves soaking the original rough specimen in a sugar solution and then boiling it in acid to deposit carbon in the available pore spaces, resulting in a dark background. The procedure is performed to reveal the excellent pinpoint fire and play-of-color of the mineral within the matrix. The face of the present, fine specimen displays predominantly red flash, with speckled orange, green, and electric blue. A side view of the stone reveals a lower band of vivid, iridescent green play-of-color. -- source link

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