At first glance boulder opals look just like lumps of rock
but when you get to know about it you will find something totally unique that looks like nothing else in the gemstone world like them.
You see, up until recent times most opals have been white or at least a pale in color. Not until the mid-18th century when they were discovered that they could be presented in a totally different manner. Veins of precious opal were discovered dispersed inside chunks of dark brown boulder ironstone.
These strips of color were impossible to extract but it was discovered that by slicing and grinding the boulder ironstone off from one edge of the vein, and leaving the other side of the stone’s color attached to the mother ironstone, a totally different effect was created.
The ironstone at the rear of boulder opals was cut in such a way that it formed the dark background of the stone, and the precious opal was polished on the ‘top’ of the stone and the color, rather than being pale, changed to a very dense brilliant display caused by the boulder in the background.
It took some time for this new type of opal to get known and be accepted by the gemstone community, many objecting to the fact that the back of the stone was not opal but rather brown ironstone. However the beauty of this amazing gem dominated over prejudice and particularly in the middle 20th century right up until today, they have come into huge demand. First in the United Kingdom, then the USA, Europe, Japan, and now China is getting in on the act.
Boulder opals can be presented as a stone with full color in the foreground or as a matrix piece, meaning that the color is mixed with ironstone in varying degrees. The more color, the more expensive. However it is noted that even when the opal has very little color, the amazing patterns and shapes in the natural boulder ironstone create a gemstone in itself and are often featured as picture stones when there is a certain likeness to other recognizable objects, or when not as ‘abstract opal’ if the pattern is just interesting to gaze at. These wonderful opal works of nature are often manufactured into opal pendants, opal rings, opal bracelets, opal earrings, to state a few variations. Gents opal jewelry are also created and often the rugged look of the boulder opals suits progressive jewelry lovers.