Diamonds ?

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Noxx

Well-known member
Joined
Feb 24, 2007
Messages
3,365
Location
Quebec, Canada
Hello Guys,
Over my two years of refining, I gathered some diamonds from scrap jewelry. Some are real and other are CZ. I have every quality. Some very clear and other very cloudy. Where could I sell them for a good price ? I'm not sure that a local jeweller will give me a fair price.

Thanks
 
Hi Noxx:

I sell all my diamonds to Blue Stone Diamond Co. You can mail your diamonds to them and they are very fast about returning you an offer for your diamonds. If for some reason, you decline the offer, they have no problems with that and promptly return them.

I don’t need to tell you, but there are diamonds and there are diamonds. Point being, 99% of folks are unable to determine the four major measuring points of diamonds. If you think determining the quality of gold is complex, this is nothing compared to evaluating the quality of diamonds. I buy quite a few diamonds in gold jewelry and I don’t pay very much for them unless they are ½ carat or larger. There is not much demand for smaller diamonds. In fact I have many diamond chips that I have accumulated over time that I just give most of them to some of my good gold selling and buying customers for their custom use.

The site for Blue Stone is

http://www.bluestone-trading.com/diamondtrade.asp

By the way if you are buying any diamonds and need a good price list on what diamonds should be purchased for, PM me and I will send you a copy of mine. I have set up a buying price list in comparison to my selling list with an 80% mark up or 40% depends on how you figure it.

Catfish
 
LOL, now I know why blue stone trading had so many specials for jewelers


Every time they get a lot in I get an email, and I assume everyone else on there list does too. They are called melle specials

I of course use the better diamonds I get for customers jobs. repair work and replacement,

The total crap I send off to a wholesaler who in turn sells them off to who knows where...zales maybe, most of there stuff is spit.

If you have diamonds and have enough to sort them and grade them by color and clarity and size you have a product that can bring a much better premium.
When I sell of the spit diamonds (they look like spit) I take the $25 to $50 per carat and am happy to get rid of it.
Even the junk crap POS diamonds are still worth 5 times there weight in gold even at todays gold prices.
Considering you most likely get them for the cost of gold from jewelry they are defiantly worth hanging on to to dump later.
Eventually they will end up in some other horrible 10k wall mart style jewelry and someone will love them.

The better stuff that is Si has a market, be happy if you get $100 pc on them. We generally buy them for about $350 for the small stuff

The good stuff is where cash is to be had. but like anything valuable its harder to come across. most people who can afford the Good VS stones and designer goods dont end up having to pawn off or recycle then.
Otherwise they trade them in. I do get some deals simply because "It Came from HIM! I'll take anything!" but that does not happen often.

If you get VS stones of good color, you can ask a premium. I pay anywhere from $600 to $900 per carat for VS goods of good color, say E-F color.
There is a night and day difference between the good stuff and the junk.

Also, if you plan on selling them, clean them!
An ultra sonic cleaner does wonders, The old hand lotion and soap scum should be removed, Ammonia works wonders for this, Also lye to get all that nasty lotion and dead skin of them.

Oil from your skin will kill the effect of a diamond as well. A trick a slimy scumbag of a dealer once showed me was to take a diamond a customer was looking to sell and wipe your thumb on your forehead or nose to get some facial oil and dirt, then rub it on top of the diamond.
"Look, see, its not as pretty as the onces we have in the case, we have to offer you less for it."

sick...absolutely sick. Anytime one slimy jeweler gets busted sales go down for hundreds of honest ones and it always makes headlines.

Anyway clean and sort them. A jeweler does not have time to do that. thats why most sorting is done by 10 year olds in India for 10 cents an hour for big lots.
If you have only a few stones and can separate out the junk, you can ask for a much better price and get a better offer. however it is known that CZs can be in the mix. A quick test to pull CZs if you do not have a diamond tester is to do this.

Draw a line with a pen on a piece of white paper.

Take a pair of tweezers and with the top of the diamond facing down and move it over the line.
If you can see the line though the bottom of the stone(read though it) or it magnifies it, its either a sapphire or a CZ or some other synthetic.

If you can not read though the stone because a diamond refracts the light so much. Its a Diamond.

Quick, fast, efficient and cheap to do.

If the diamond does not have a lot of sparkle, its junk.
 
Whats funny is that Blue Stone trading has there office above a funeral home- Too funny but true!

I am a jeweler and over the last 2 - 3 years small sizes diamond prices have decreased substantially due to automation in the cutting sector and increase in supplies from cutting plants in India and Vietnam=

The problem with small diamonds is that in a given jewelry item the stones may or may not be properly matched for color, clarity and cut. Therefore when you end up with a lot of small stones they have to be sorted and most folks I know end up with large bags of these stones and the time it takes to sort them outweighs the selling price when you consider the value of the sorting time ( assuming that its done here in the USA).

Diamonds that are large take little time to examine and sort- I buy diamonds 1- 10cts each whenever I can so long as I can buy them at a reduced cost. The reason for the reduce cost is that in the diamond market if you are a reputable and credit Worthy jeweler you can get diamonds in overnight on consignment for a short term with minimal costs - so if you can get one at "Market Price" anytime of the week there has to be an incentive for you to lay out the cash and buy a diamond then sit on it until it sells. Diamonds do not sell everyday as many would like to think under most cases.

Folks think diamonds are rare- most jewelers will tell you that cash is rare as it can be used to buy most anything-

If you get small diamonds in with your scrap - tend to consider them them as a Small bonus and do not spend too much on them as the time to sort and efforts to sell will eat up profit quickly on them- and if there are CZs ( cubic zirconias) mixed in with the bunch then plan on spending time to pick all those out too-

If anyone has ?'s on diamonds feel free to message me- I have been doing this all my life -
 
Diamonds are very good conductors of heat. There are reasonably priced instruments that allow you to test a stone very quickly.

Some of the older cut stones such as rose cut, might be mistaken for junk. A thermal tester will allow you to sort a batch of mixed stones and not miss any.
 
Good point Irons-

But testing mêlée diamonds one by one is a pain with a thermal conductor probe- some folks use an ultra violet light and sort them by the color of their florescence instead.

You can also weigh them one by one as CZs weigh more than diamonds-
 
One of the ways I spot CZs quickly is to put them table down and look for an eye. Since the CZs have a different index of refraction, cutting them with the same proportions as a diamond brilliant changes the optical properties and leaves a non-reflective hole that looks like a dilated pupil.

Dispersion is another important property of Diamonds. The colors of Diamond dispersion are another clue.

Back to the point of oil and Diamonds. Crystalline Carbon has a high affinity for oil. Placer stones need to be cleaned before they will stick well to a grease table because they pick up a coating of organic material in the environment over the eons.
 
Yes,
CZs have higher dispersion than diamonds so they show prismatic colors a little more. I find that it much easier to use a diamond/moissonite tester on the stones before they are dismounted. Sorting through a pile of unknown loose stones can take some time. Although, one still has to watch out for the occasional CZ that has been used to replace a missing diamond.

I can usually spot a CZ easily with my eye - they have watery appearance - but sometimes I have to test to be sure.
 
I would think the easiest method is the scratch test. Tungsten carbide will not scratch diamond and a carbide tipped pen is easily found at Home Depot or wherever. It's pretty crude but it will distinguish diamonds from the rest, even moissanite (crystalline SiC and WC won't really scratch each other).



I tend to keep away from UV because it it damaging to your eyes. What wavelengths are recommended?
 
That is true!! The thought had crossed my mind when I was typing that; they are crystals after all. That's why it's always a scary when a large stone must be cleaved-the stone could shatter or cleave improperly if the cutter made a mistake.

That said, it would probably be less stressful to the crystalline structure if the diamond were to scratch something else, rather than have something be scraped against it. I must admit, I do not know enough about this form of carbon's cleavage planes so I'm still hesitant to say that it would be better one way or the other.




I wonder about the fluorescence test--I do not have any real experience using that. I have variable wavelength UV bulbs that would probably work quite well, but as I understand it, some diamonds fluoresce, some do not. It's entirely based on what they've been [naturally] doped with i.e. boron, nitrogen, etc.

I think the best bet would probably be some sort of spectographic technique. Come to think of it, I have some UV specs I could possibly use...
 
IF you don't mind loosing the CZ's drop all the stones in nitric the Diamonds will cleanup and the CZ will dissolve. Or so I was told by a jeweler friend of mine.

Ray
 
CZ vs Diamond - Detectable to the Naked Eye

Light Dispersion: Greater prismatic effect of CZ creates an abnormally high amount of fire
Lack of Flaws: CZ is virtually flawless, most natural diamonds have some inclusions
Color: CZ can take on a gray tone when exposed to sunlight for prolonged periods
CZ vs Diamond - Detectable With Testing

Fluorescence : Under shortwave UV light, CZ typically luminesces a greenish yellow color
Refractive Index: Cubic Zirconia refractive index of 1.800 - 2.170, Diamond's RI is 2.417
Thermal Conductivity: CZ is a thermal insulator, natural diamond is a thermal conductor
Weight: Cubic Zirconia is heavier than diamond in a given size
Another method for distinguishing Cubic Zirconia from diamond is to mark the stone with a grease pencil or felt-tipped pen. Natural diamonds attract grease, while a Cubic Zirconia will repel grease. You can also Inspect the facet edges with a 10x loupe to look for any chipping or slightly rounded (not sharp) facet edges that are telltale signs of Cubic Zirconia.
 
Thanks for the advice! Obviously you've done your share of work with these stones.



The curiosity I have is if you have a flawless diamond produced by a vapour deposition technique. That is very rare yes, but so is a flawless, colourless natural stone. A friend of a friend of a friend of mine is a materials scientist that developed a process that allows for fairly large diamonds to be grown and occasionally some of the product will be of such quality as to render it indistinguishable by conventional methods. I have read that such stones are DeBeers' worst nightmare. I suppose they could be detected because they are too perfect. Still I envy his position--on occasion he could have a flawless ''rough'' (although I heard that they are in fact oblong rectangles 1.5 cm by perhaps .75 cm long). Still, serious caratage.


Lou
.
 
First off i'd like to say that I am a noobe to this forum. I have been scoping it out for several months now, and am VERY impressed with the info here. I am a jeweler of 38 years which means nothing more than I am an old guy. I have been refining my own scraps, and filings for about 33 years (ever since I got ripped off by a local refiner)
Anyway, I think I can shead some lite on the dia/cz thing.
Z's will not dissolve in HNO3---------
The line trick doesn't work well unless you have large (1/2 ct. or larger stones), and even then it will only tell you weather or not the stones in question are doubly refractive of not. This differentiates between dias and moissanite, or a few other clear dia substitutes.--------- Those thermal testers that were mentioned elsewhere on this page work very well. The only problem is that you HAVE to buy the high dollar machine that will also test moisenite. (by high dollar I mean about 150 bucks)(Google dia/moisenite testers) Small stones are kind of a pain to test because they are hard to hold. So when ordering your tester you should probably order a pair of diamond tweezers.----------The easiest way though to test a lot of melee at one time, or even large stones, if you have any, is to use specific gravity liquids. The SG of diamond is 3.51-3.52, very little variation. All other dia substitutes that even remotely look like a diamond, are much heavier and will sink in a liquid with a SG of 3.52, or even higher. A liquid of SG 4.00 is a good one to get. The diamond will stay at any level you put it in the 3.52 liquid. AND it will float in any liquid with a SG greater than ,lets say 4.00. Synthetic corundum (sapp), YAG, stroniun titanate, CZ etc. are ALL much heavier, and will sink in the 4.00 SG liquid. Keep in mind that the stones to be tested MUST be brain surgery clean before testing. Drop them in the liquid and knock them below the surface to breakthe surface tension of the liquid. --------CZ's are 1.88 times heavier than a diamond of the same size, so if the diameter measurement says that the stone in question should weigh 1ct., and it weighs 1.8, you know that are probably playing with a "Z"---------ALSO the UV light thing doesn't work because not all, probably less than 25%of all diamonds fluoress. Hopefully this info will help someone. If you need to, feel free to e-mail me if you think I can be of some help.
Thanks again for the info on this forum.
Please excuse the spelling and any typo's-------I can't type.
shooter/jeweler
 
Not all but many CZs will fluoresce a light yellow due to the stabilizers that they cook into the mix when they produce them to make clearer stones-

Most diamonds tend not to flouresce this color - some do but not all

The heavy liquids is a good idea and does work -

Whatever works for you is what you should stick with

Lots of ways to skin a cat
 
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