Buying and selling diamonds

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catfish

Well-known member
Joined
Mar 20, 2007
Messages
159
I have received several requests for information on buying, and selling diamonds and gemstones. I thought I would post the following information so any one that is interested in this type of activity will at least have some of the basic information.

First of all let me advise you that I have been buying and selling diamonds for the past couple of years or so. I am still a neophyte. I learned the basics from my son, who has been in the business for several years and has been quite successful in this business.

Buying and reselling diamonds is a very serious business and requires a very comprehensive knowledge of diamonds and also the market for reselling same. There is a 900% markup in the price of diamonds from the jeweler to the buyer of used diamonds.

I do not fool with any type of gemstones at all. There are too many variables involved in determining the type of gemstone, quality and most important of all the value. The diamond and gemstone business reminds me of the age old adage “beauty is only in the eye of the beholder”.

I will attempt to post a few very important things one must be aware of in the diamond business. The first rule of business is “Supply and Demand”. There are a lot of diamonds on the open market and there is a market for them. The key is being able to determine a fair purchase value and be able to sell the diamond at a profit. Just like the used car business.

How to determine the quality of a diamond:

1. Test the diamond with a good diamond tester.
2. Make sure the diamond is not a synthetic such as Cubic Zirconium or Moissanite. A state of the art diamond tester will perform these tests with good results.
3. Once you have determined that the stone is a real diamond, then measure the stone diameter or width and length, depending upon the cut. You will need a diamond measuring device or a good pair of calipers that measure in metric.
4. Once you have determined the type of diamond, style of the cut and then you need to analyze the clarity, cut, and color.
5. Remember that diamonds are evaluated by the four (4) C’s, Cut, Clarity, Color, and Carat. Each of these components has many different scales, such as color have approximately 26 different values and etc.
6. Like I said earlier, there are many many different components to evaluating a diamond. The most common categories are as follows:

The Basics of buying Diamonds

Size in Brilliant Brilliant European European Mine Cut
Points Flawless with Flaw Flawless with Flaw
(Carat) Minor Minor

6.25 $1.00 .50 .50 .25 N/A
12.5 $2.00 1.00 .75 .50 .25
18.75 $2.25 1.25 1.25 .75 .50
25 $2.50 1.50 1.50 1.00 .75
50 $5.00 2.75 2.75 2.00 1.25
100 $8.00 4.50 4.50 4.00 2.50

This list denotes the points in carat and price per point. 100 points equals 1.0 carat and it will weight 200 milligrams or .200 grams. And if the diamond is of good quality, I would offer about $450.00 for it. Most diamonds you will run into will be small, from 1/8th to 1/2nd carat. Do not buy chips. They are worthless.

Note; a good way to tell a synthetic from a diamond is weight it. CZ and Moissanite weighs about 75% more than a diamond.

If you are serious about this business, I strongly suggest that you purchase the following books and study the ins and outs about evaluating diamonds and gemstones.

“Diamonds Buying Guide”, by Antoinette Matlins, P.G.

“Colored Gemstones Buying Guide”, by Antoinette Matlins, P.G.

Now, for a couple of personal pointers. You will seldom run into a flawless diamond in the open market. I always purchase at the Brilliant with minor flaw or less. Depends on the evaluation of the diamond. I do not bargain or hassle over the buy price. I make an offer on the above scale and if they accept fine and if not fine, go to the next one. You don’t want to get all the diamond business, just the ones you can make money on.

A buyer of diamonds that I have used and had good luck with so far. I sell most of my diamonds (the ones that my wife doesn’t get first) to private buyers at a hundred percent markup..

The folks that will buy your diamonds and also the gold or silver they are set in.

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

By the way they will give you 97% spot for your gold, no hidden fees.

Another site you may want to copy all their precious gems specifications, are as follows:

http://www.burma-ruby-sapphire.com/index.htm

You may want to develop your own price list, but I will share this one for you to start with.

If you have any additional questions or concerns, PM me back and I will try to address them.

Catfish

PS> The message board on the forum doesnt like any type of formating. If you want the suggested buy price list just PM me with your email address and I will send it to you.
 
Thanks for sharing, Catfish. That's some great info. May I ask which brand of electronic diamond tester that you own? I have seen several for sale on Ebay. It is my understanding that you need two devices....one to tell diamonds from other stones.....and then a separate device to tell diamonds from moissanite. I am ordering a Mizar device to test gold....just not real sure about a diamond tester. Thanks again for the info.

James
 
James:

I have a diamond tester manufactured bt RS Mizar. Called a Diamond Detective. Current sale price $89.00. Yes you are correct, the diamond tester will not test for moissanite. I have a seperate tester to determine the stone that tests as diamond for moissanite. The one I have is manufactured by TRI Electronics and is called Moissanite Tester. $120.00.

I purchased both test sets from Kassoy Jeweler's Supply in 2005. I understand that there is a more expensive test set available today that will perform both tests.

If you don't have a moissanite tester, you can always weigh the stone if it is loose. A synthetic will weigh about nearly three milligrams per point, compared to 2 milligrams per point of a diamond.

I hope this helps.

Catfish
 
Thanks, Catfish for the great info!

I have the book "Gem Identification" by Matlins and Bronanno

It has a chapter on buying antique and estate jewelry.

I will need to get the one on diamonds.

Catfish is right there is a lot too all this. All kinds of ways to fake stones included pasting a real diamond on top of glass! Called a doublet.

I just picked up a Ceres Dual XL tester off of e-bay for around $185.00 test for cz and moissanites. I just got it and tried it on a real known diamond I had here and a ring with a stone that looked like a diamond it spotted both. Real and fake. They sell a less expensive version of this tester but the batteries are build in. I think you recharge them. non-removable? I wanted one where I could take the batteries in and out.

I also pickup a loupe comparator from a place call surplus shed for $28.00 plus shipping. It seem very well made and has mm marking on a glass type lens to measure stones.

I will keep you posted on how this one works out for me.

Keep up the great info Catfish!!!
Dgoldboy
 
Let me start this post by saying I am a chemist not a gemologist. To this day I cannot tell a CZ from the real deal. But this thread is 18 years old and since we do not delete threads, members still can access and read this thread, as I just noticed a member doing.

So my request is that a member who is experienced identifying diamonds update this thread because in the last 18 years new testers have come along and lab grown diamonds are also common. Some more recent updates about testers and lab grown diamonds will be appreciated.
 

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