The Southern Lights Necklace - 64 carats of South Australian Crystal Opal, set in Platinum and Diamonds

Last year (2014) I was at a public auction where several lots of South Australian crystal opal came up. They were part of an estate, acquired many years earlier, and obviously from one parcel of stones that all matched. The auctioneers had split them to try and maximise the price.

None met reserve and I put in a low ball offer afterwards, to my surprise I got them all without further negotiation, 80 carats of opal in total.

I took them to Opal Pacific in Auckland, who told me the parcel was worth anything from $200 to $500 per carat (wholesale), depending on what I did with it. Apparently Australian crystal is soaring in value as International buyers realise Ethiopian opal is unstable, and they're now buying Australian stones again to meet their customers' requirements.

So decision time. I laid the stones out and they kind of made their own decisions. The necklace you see above is made up from the stones I'd bought, grouped into a necklace. Opal Pacific matched them up, worked out the orientations for the best play of colour, and then cut and polished them to size.

I've always liked the old spectacle frame Nouveau and Edwardian opal necklaces, and decided to give that look a twist, super size the opals, set them in platinum, and put in a few diamonds as accents. Opal Pacific did a marvelous job turning my ideas into the reality you see above.

It's a pretty cool look, and it was only after the job was done that we realised just how good those opals were. They have an extraordinary play of colour between greens, reds, and rainbow colours.

So we've named this necklace "The Southern Lights", after the Antarctic light show which is our New Zealand equivalent of the Northern Lights.

The Southern Lights, known as the Aurora Australis, plays across the Southern Skys above Antarctica, and continually changes colour, just like these opals.