Opals: a gem stone on LSD

I had to cut an opal for a white gold pendant that I made on commission this week. It got me thinking about how crazy they are.
So what’s going on here and are they unlucky?

Let’s kill that one for a start: The notion that opals are unlucky for anyone who is not born in October (the month for which opal is a birthstone) does not derive from ancient wisdom of those who lived closer to the earth than we do and knew the secrets of the cosmos in a way that we have forgotten, but rather from the novelist Sir Walter Scott in 1829 when he used it as a notion in his novel Anne of Geierstein.

Now we can all relax.

The ludicrous kaleidoscope of flashing colours in a good opal is caused by layers of tiny silica spheres that were laid down by water leaching through rocks and filling natural voids and fissures. The water evaporated and the silica was left behind in successive layers. It’s these tiny spheres that refract the light and throw out all these amazing colours. Needless to say, this process took a while. They reckon about 5 million years to produce 1cm of opal, so don’t try this at home.

There’s a lot of variation in opal and the best stones are just a riot of colours. Most of the commercial gem stones are what I describe as ‘milk and magic’; flecks of blue and green within a  white matrix. Often there’s a lot more milk than magic. The better stones, of course, command a higher price. Opals are fragile so  I sourced a stone as a backup for the opal in this pendant in case the one I was cutting broke. It would have cost me £408 had I needed it which was £78 more than the price I quoted for the finished pendant.

No wonder I’m going grey.