Ruby?

[sga]

Hi,

Just wondering if there are any gemstone experts out there?

I bought some 'ruby' beads from a bead shop for about £1.50 each (4mm facetted). I thought that, since they were ruby, I could try soldering a ring with one in place. But it turned white with the heat. I thought rubies could take heat. Or at least if they couldn't it would crack as opposed to changing colour. I did quench it in water (oops). The bead shop says it's probably a treatment and they really should only have been used for stringing. I'm not interested in playing the blame game with them, but I'm just interested in knowing whether this can actually happen with a real ruby? I have tested another (tiny!) ruby bead bought from another source, with direct heat, and it didn't go white (glowed orange for a bit though :-)

Thanks

S

[Dennis]

Dear sga,

No expert I, but if you take Cooksons rubies as a guide, a 4.0mm faceted Burma ruby is about £25.00 plus vat. They are valued by the carat, so a bead would cost much more. You can also buy synthetic rubies, which are made from aluminium oxide and a colouring agent.

Some years back I used synthetic red stones from Holts in Hatton Garden, embedded in PMC prior to firing without problems. However I did let them air-cool to avoid fracture. They cost very little, so I suggest you use those. Regards, Dennis.

[sga]

Thanks for your reply Dennis, it sounds like maybe they are synthetic. They surely must be dyed if they go white! Anyways, live and learn. Thanks for the tips. I love that this is such a learning experience. I had never even realised you should air-cool rubies until I started researching. Maybe I'll steer clear of experimenting with real precious gems!

Sharon

[ps_bond]

Synthetic - or lab grown - rubies are chemically & structurally the same as mined/natural rubies; heat treatment of rubies is commonplace, according to both what I've read & suppliers I've spoken to. Other treatments that are slightly less common include glass-filling and some surface colour treatments.

I'd be very surprised if your beads had much in common with rubies beyond the colour...

[sga]

Ah, I see, synthetic is the wrong word then. Fake would be a better description! I guess that kind of error could potentially be a lot more expensive, but they were just beads. I'm going to Sri Lanka in a few months though. I shall definitely be keeping my money in my pocket near any 'too good to be true' gem deals there! (or any gem deals actually).

Sharon