View Full Version : Moissanite the devil in disguise ?

01-05-2013, 10:59 AM
I note that Cooksons are now selling Moissanite as part of the range of stones, I truly believe this stuff shouldn't be near our business, life is tough enough without this being in general circulation, leaving the less scrupulous the ability to very easily pass it off a diamond to the less aware. As honest as the jeweller may be when he sells a carat stone, explaining all about its properties and low price etc , but once its out there its nothing but potential trouble.

I have been threatened by a very irate ( and large) customer accusing me of swapping and 1.5ct round diamond for a Moissanite in a ring I had taken in for a resize, the 6000 he wanted from me at the time could quite easily ruined my business, I was actually able to prove I hadn't but not before a lot of ill feeling and police involvement
Its bad news and if Cooksons want to sell it they should hand out Moissanite testers ( that work ! because most of them don't) to all their account holders .

Be interested what anyone thinks ?


01-05-2013, 11:25 AM
An interesting one - feeds into the whole gemstone identification & trust issues discussed elsewhere.

I see that the thermal conductivity is quite close to that of diamond; I'd have hoped that the birefringence was an obvious indicator although I've not handled them. I probably ought to get one to see...

I've no real issue with people selling diamond simulants as simulants - the problem (obviously) comes when there isn't full disclosure.

01-05-2013, 01:32 PM
Are there straightforward ways to test gemstones without expensive equipment? Surely there are already lots of problems out there with people selling cz or glass as real stones? Personally I quite like the idea of moissanite as it's cheaper than diamonds but still looks good...BUT obviously I would be very clear about what the gem is when selling!

Keith - that sounds like a horrible situation to deal with! I reckon your customer was a bit of a con-artist, I wouldn't be surprised if he'd tried that on in other jeweller's as well.


01-05-2013, 05:07 PM
Short version - "no". There are some inexpensive tools that'll give some confidence, but to know 100% takes the more expensive stuff. http://www.amazon.co.uk/Gem-Identification-Made-Easy-Hands-/dp/0943763908 has some good stuff on identification using loupe, dichroscope and Chelsea filter as the basic tools - most of the time it boils down to "it definitely isn't x, it might be y". Refractive indices and specific gravity (if it isn't set) are useful - but there's overlapping ranges on a lot.

01-05-2013, 09:55 PM
Hhhmmm, have heard that similar tale a few times now, sadly though moissanite seems to be too close an imposter........hence the move to machines (when they work), that distinguish between diamond and moissanite. If I'm asked to work with a customer provided diamond, I always test it with the customer present or at the very least, without disturbing the original setting.

Gemstones are a minefield!!!!!!!!!!!!!!!

02-05-2013, 04:59 AM
I bought a Moissanite stone with a speil about how they make them etc. It says that they are the same compound as diamonds and that they behave the same, basically factory made diamonds. It has its own certificate, and I have to say its very sparkly. I cant remember exactly how much it was but it was around the 30 mark, think the stone was around 3mm, not sure unless I measure later. What is the difference between a good quality CZ and a Moissanite. are the materials or manufacturing process different then. Back a while ago I ordered some cheap 1mm diamonds from Cookies and some 1mm cz's and ended up putting the cz's in the ring because they sparkled more than the diamonds.
Dazed and very confused !!!!!!!

21-07-2013, 07:21 PM
I bought a moissanite a few years ago from Rio Grande in the US, and whilst it is very pretty, in a certain light and from a certain angle it looks quite green. I did read somewhere that this was the norm for moissanite.

22-07-2013, 08:18 AM
From memory its made of silicon carbide, which is different of course to "neat" carbon which is what diamond is made of. The gemmological association of Great Britain I believe runs courses on how to spot the difference. It's actually not that difficult when you know what to look for. I remember when CZ fist came out and everyone was in a panic, and now most people are able to spot the difference between that and a diamond.
Jasmin - yes most moissanite does have a green tinge to it in certain light which of course does help! Most are the equivalent to I-L colour. They are also doubly refractive as opposed to diamond which are singly refractive, and when looking into the stone from the upper girdle facets down into the base of the stone, you can quite often see doubling of the facet edges, like natural zircon.

29-07-2013, 02:32 PM
I see on the IJL programme of seminars there is a seminar called "Colourless with confidence" being held on September 1st starting a 4.15 in the afternoon.. It's being run by GemA and will show you how to sport the difference between diamond, cz and moissanite.