What gives a Boulder Opal its value?

We currently have a stunning range of Premium Boulder Opals in stock – each one brilliant and one of a kind. They are notably higher in price than our previous selections of Boulder Opals, so what is it that gives a Boulder Opal its value?


Boulder Opals are easily distinguished by their layer of solid brown ironstone left on the back of the stone. Boulder Opals are mined from large ironstone boulders under the ground. Thin veins of colourful opal forms in the cracks and fissures in these boulders which are cut into the stones we sell.

Boulder Opals usually have a flat surface or an undulating surface and are almost always cut in a freeform shape to maximise the size of the stone. The quality of the work of the opal cutter affects the value of the gem as it should be polished so that no scratches or imperfections are visible to the eye.

Boulder Opals are valued by their colour, the number of colours, size and coverage of flash (the play of colour, sparkle within the stone) with red being most valuable followed by violet, orange, yellow, green and blue. The intensity of colour, pattern and the clarity are also very important.