Andamooka, South Australia
A cabinet specimen of large porportions, this is an extremely fine example of a matrix opal from the classic source for the mineral. Speckled with electric blues and greens on one face of the boulder, flagstone patterns of color abound on the contour polished top while bands of color are visible on the sides. Like all matrix opal 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.
Weighing approximately 3786 carats and measuring 5 x 3 1/2 x 2 1/2 in