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 Replies: 10 / Views: 2,589 |
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Pillar of the Community
United Kingdom
1563 Posts |
Sorry this is off topic but thought some of the guys here might have the answer for me.
I get passed on to me a heck of a lot of gold rings, mainly 9ct and 14ct with the occasional 22ct.
What I need to learn is how to distinguish what stones are what, in particular what's glass and what's diamond. The reason being is I sell them on at a small profit but sometimes I wonder if I am giving away too much as I generally value the rings on the approximate weight of gold in them and the current spot price.
I have tried google but it gave me a headache after a few hours, anyone able to help me with this one? You will never soar like an eagle if you hang around with turkeys.....
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Moderator
 United States
16677 Posts |
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Pillar of the Community
United States
4897 Posts |
Those hand held machines are ok. It is not really too difficult to tell a diamond. Most you are likely to see will have inclusions and or carbon spots. If it looks too perfect in clarity and color it is likely not diamond. Where it gets tough is Moissonite ( http://en.wikipedia.org/wiki/Moissanite )it will fool most electronic testers. |
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Moderator
United States
16677 Posts |
I've got emeralds and rubies down pretty good from their lab created counterparts.
Diamonds cut, not so much :)
swcoin.ecrater.com
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Pillar of the Community
United States
3670 Posts |
Diamonds remind me of comic books and baseball cards oddly enough in value at least, as one being paper so fragile and the other diamonds of course being on other end of spectrum. Most worth nothing but some in right condition graded worth big money....
Similar in the fact that MOST ain't worth the time to make itno jewelry. Most diamonds under 1/2 cc is basic chipped junk IMO, minus being a GREAT high grade of course or multi ccz....
Diamonds of course need a good cut, color, and clarity, while the few examples that are real gems can be worth HUGE amounts of money....
Of-course nothing adds value to a diamond like a IGA certification....
I once worked at Southern Bullion and a gold kiosk so I have a little bit of experience dealing with fine jewelry....
Edited by Silverhawk74
08/25/2013 12:23 am
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Bedrock of the Community
Australia
21786 Posts |
I am a gem cutter, and have done some study in gemnology. It is a specialised branch of materials science.
Gemnology is the science and the study and the identification of gemstones and their fakes and simulants.
To properly and conclusively authenticate a gemstome requires some basic scientific instruments.
If you have a stone that requires authentication, I would suggest that a professional gemnologist be consulted. There are very few of them, and they are usually employed by leading jewelry businesses.
I have a gemstone collection, with about 500 specimens, where most of the natural, (as opposed to 'created' or 'synthetic' stones), would be less than a carat in weight. Some of my 'created' stones are up to about 50 carats in weight.
Don't be fooled by the commercial term 'created'. It means exactly the same thing as 'synthetic'.
Instruments for measuring mass, density, dimensions, light filters, ultra violet light reaction, refractivity, colour dispersion, and birefringence are commonly found in a gemnologist's laboratory. A gem microscope is also an essential tool.
There are specialized instruments for the identification of diamonds, which include electrical conductivity and temperature conductivity contact probes.
I have some of these instruments. I also have a reasonable reference library on gemnology, and some supporting books on mineralogy and geology.
If you wish to have a suspect gemstone authenticated, you must consider the cost of such services first, and decide if they are justified.
Edited by sel_69l
08/25/2013 11:34 am
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Pillar of the Community
United States
3670 Posts |
I think it is safe to say Sel has more or atleast as much time and exp in the gemstone field as anybody on this site, so I would definitely suggest making notes of his thoughts on the subject....
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Pillar of the Community
 United Kingdom
1563 Posts |
Firstly, I have ordered a 'diamond' tester, though after in depth reading about them, I doubt for 8 quid they will be accurate. Secondly, I know sel_69l from other posts and regard his info as excellent. Thirdly, All I need is a simple guide to follow so that I am not selling a 14ct ring set with stones for 40 quid based on gold content when the actual item is worth a lot more if I could give a true and full description. Very often I sell rings set with stones and then they appear a few weeks later at a massive increase in price. Lets Imagine I am selling a nice 9ct gold ring on ebay, weight is 3 grams.... easy.... worth about 33 quid.... BUT it is full of marks on the inside and has a cluster of gorgeous looking stones that may be diamond. I just need a few pointers to send me in the correct direction here. Come on sel_69l I know you can educate me!  You will never soar like an eagle if you hang around with turkeys.....
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Bedrock of the Community
Australia
21786 Posts |
Unfortunately, it's a bit like a numismatic novice attempting to identify European hammered coins for himself.
If the numismatic novice really wants to know anything about them, false coins or not, he will take them to a coin dealer, who, hopefully, is a specialist in this area.
Like the coin dealer, I would need to have the gems 'in hand' to be able to make any specific comment that may be halfway worthwhile.
It must be remembered that I am NOT a specialist gemnologist. I have read a bit in this area, and I have a few basic gemnological instruments for my own needs. I have to admit, that if I have a gem that may potentially be very valuable, I will defer to a professional. Fortunately for me, I know a couple of them.
My main motivation in learning something about gemnology is to learn what is relevent to the stone that I may be cutting. I mainly use a refractomoter, to determine the critical cutting angles that I may be restricted to. Sometimes, I will use a Chelsea filter to test authenticity for emerald. I have a Chelsea filter, because they are cheap to buy.
I use a 20x loupe, with a very narrow depth of field, to examine the internal flaws inside a gemstone. Such flaws could tell me where NOT to cut, or wheather to remove from the gemstone rough altogether, before cutting.
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The cost of testing for diamonds as a gem species may be relatively cheap. A pair of simple contact probes can be placed on opposite of the stone to be tested. The stone is tested for thermal conductivity. Diamond is a conductor of heat, and cubic zirconia, (by far and away the best of the diamond simulants), is an insulator to heat.
Edited by sel_69l
08/26/2013 02:17 am
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Valued Member
United States
477 Posts |
Wow, this is some great information. Thanks to the experts.
Rick
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Pillar of the Community
Canada
3692 Posts |
You want to look for bearded girdles and sharp facet junctions. And check for fluorescence. That's all I'm going to say.
A little bit of research and lots of experience will tell you if they're diamonds or not.
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Replies: 10 / Views: 2,589 |
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Posted 08/24/2013 6:44 pm
