I've written about opal a few times now and, as we're in October and Opal is one of it's birthstones, I'd thought that I might tell you about one Opal in particular.
This Opal is called the Halley's Comet opal and no, it didn't come from a comet although when I heard about it, that's what I thought too! After all, Peridot has been found in asteroids so it wouldn't be too much of a stretch :-)
It's called Halley's Comet as it was found in November 1986 in Australia as the Comet was passing through the southern skies at the time it was discovered and is only visible every 75 years. Five Australian miner's known as the "Lunatic Hill Syndicate" found the gem, the largest uncut black opal in the world, at an open-cut mine near the famous Lightning Ridge in New South Wales. It weighs nearly 2.000 carats (!), is about the size of a man's fist and is thought to have formed around 20 million years ago, phew! The Syndicate was made up two brothers and a small company that provided earth-moving equipment. "Lunatic Hill" got it's name back when mining first started at the site. Opals could be found just a few feet below the surface in the shallow flats below the hill so that's where the most experienced prospectors stayed. Why would you need to go to the top of the hill? Only a madman would start up there, you'd have to dig for a very long time to find anything. But this is exactly what this syndicate did and the Halley's Comet Opal was found 20m below the surface! Just goes to show, just because someone thinks your're mad to do something, doesn't mean you're wrong!