Monday, 3 August 2009

Opals !!!!

(New 30mm marble with opal, now on Etsy!)

Unlike ‘soft’ glass, working with borosilicate has some limitations of colours, ways of working, and what can be put inside. For a start buying it can be fraught with difficulties, I only know a few people using it in this county, and getting supplies is tricky. In the USA there are lots more people using it, which means more trade and it’s easier to get the more difficult items. Last week I had to launch a desperate plea on the Frit Happens website for one special effects rod rather than trying to put together an expensive import from the USA!

The USA have been using boro much longer than here, one of the amazing things discovered by some USA lampworkers that although many items can’t be used easily in borosilicate (gold and silver evaporate before the glass thinks of melting!) that one strange opal has the right properties for being encased in borosilicate (pyrex)

In France in 1974 Pierre Gilson was able to create the first synthetic opals. These weren’t bad imitations made with plastic and glass; they are physically and chemically opals, made by copying the extreme pressures and temperatures over very long periods (some can take 12-18months to form) that naturally make opals. It’s only under a microscope that they can be seen as different as they have no flaws like normal opals, so makes them stronger!

The best bit (for me!) is unlike natural formed opals they have no water content! Coupled with having same expansion rate as borosilicate it means they can be encased without cracking or exploding!

I bought a few some months ago, but as they still aren’t cheap it’s taken me a while to get the nerve up to try them out. I posted a picture on last weeks blog showing one; they make such amazing ethereal planets. I managed to get some tiny dot bubbled orbiting one which was a wonderful effect. I started on a second one I was just about to tidy the marble up and get rid of some of the extra bubbles & knocks when the gas ran out! Argh! I’m still debating whether to break it up for the opal, or sell it as a second as I can’t re-melt this one because the red glass in it might go a nasty colour if I do.
(My first Marble with a Gilson Opal!)

I have now made a very large 30mm marble (about 1 1/8 inch) with a lovely galaxy swirl, originally I was going to put the opal in the centre but it wanted to orbit on the arm which I think looks better as it breaks up the symmetry. Underneath I’ve done some lava-lamp effects with whispy yellow, green-yellow and blue glass, and a simple cobalt blue backing. It’s now in my Etsy shop, a little more expensive than some of my previous marbles, but it is rather special! I’ve really enjoyed working with these little treasures, and hope to include a few more as I really like the ethereal feel they give to my little landscapes, or should that be galaxy-scapes?

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