03912.0 - 14 Kt Yellow Gold pendant 30x15 mm With Treated Australian Opal Matrix

Detailed Condtion : All imperfections, if any, will be clearly visible when viewed in the highly magnified photos attached.

This Treated Opal Matrix is from the late 1960's and was set into this handmade pendant in the late 1980's.

The Andamooka Opal Fields, near Lake Torrens in South Australia, produced a certain type of Opal in a matrix form which could cause the whole stone to be very porous.
The rough stone would have a chalk like white appearance which would overwhelm the tiny granules of colourful Opal mixed within and the two would be blended together so that it was hard to see anything else but white.
Such stones could be treated to enhance the colours of the Opal mixed within it.
If a stone was so porous that if touched by one's tongue and it would stick to the tongue, then it was definitely treatable.

The treatment was basically to soak the stone, after having been cut and polished, in a sugar solution, which the stone would absorb.
The stone would then be taken out and left to dry and once completely dry there would be sugar left inside.
The stone would then be soaked in acid which would burn the sugar black.
With that, the Opal would be readily visible against the black background.

This is basically the same principle behind making Opal Doublets and Opal Triplets; take a thin slice of white Opal, paint the back of the slice black and the colours become very strong and visible, even in low grade Opal.

A solid Black Opal with an appearance anywhere near like this pendant, would be worth tens of thousands of dollars.
Some of these Treated Opal Matrix stones were so good that they were passed on as Black Opal, which they are not.
 
We do not import, promote or sell Synthetic or Man Made Opal, nor any non-Australian mined Opal.

On 27 July, 1993, The Australian Government proclaimed Opal as the National Gemstone of Australia!