Do You Think You Found a Diamond? Learn How to Identify Rough Diamonds (2024)

Every week I get an email from somebody that thinks they found a diamond. Maybe you are reading this because you think you found a diamond. This article will tell you how, and how not to identify rough diamonds as they are found in nature.

The chances of finding a rough diamond are extremely rare. Odds are you didnot find a diamond. First a few questions:

1. Is the suspected diamonds larger than 8 mm (3/8 of an inch)?

2. Does the suspect diamond weigh more than 2 grams (10 carats)?

3. Did you find more than one suspected diamond?

If the answer to any of those questions is YES, then I have bad news- you probably did NOT find a diamond.

Diamonds over 8 mm, in excess of 2 grams in weight are extremely rare. Thechances of finding a diamond are 1 in 10,000,000. The chances of findinga diamond over 8 mm, in excess of 2 grams in weight are 1 in 1,000,000,000.That is one chance in a billion!

OK, so you think you beat the odds and actually found a rough diamond. Nowhow do you test it to confirm it is a diamond?

Crystal Form:

Looking at the crystal form is a quick way of differentiating diamond frommost of the other minerals that look like diamond.

Diamonds are cubic (isometric) form. The most common mineral that looks likea diamond is quartz and it is hexagonal form. When looking down on the crystalsfrom the top, with the point of the crystal aimed at your eye, quartz willhave six sides and a diamond will have four sides. If you see six sides thanyou probably found quartz.

Fracture:

When diamonds break, they will cleave creating smooth, flat surfaces. Quartzand glass will create conchoidal surfaces when they break.

If you see curved conchoidal surfaces (see photo above) then you know yoursample is not a diamond.

Test Hardness:

You CANNOT test the suspect diamond by scratching glass.

Many minerals scratch glass. Glass is 5.5 on the Moh's Scale of Hardness.The following list is of common minerals that scratch glass, may look likediamond and they are much more common the diamonds:

So do not try scratching glass with the suspected diamond. The onlyhardness test that will identify a diamond is scratching corundum.Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale.If your suspected diamond crystal can scratch corundum, then there is a goodchance that you found a diamond. But NO OTHER HARDNESS TEST will identifya diamond.

Click here to buy inexpensive corundum crystalsfor testing diamond hardness.

Test Specific Gravity:

Testing for specific gravity will determine the density of a diamond. Actualdiamond has a density of 3.5 - 3.53 g/cm3 and you can use this easy hometest for specific gravity at: SimpleSpecific Gravity Test at Home.

But this test is difficult to perform accurately on small samples. If yoursample is large, then you failed the question 1 in the first section. Ifyour sample is small, then the accuracy is poor. So unless you have accessto a laboratory scale then I suggest skipping the specific gravity test.

Test for Thermal Absorption:

Diamonds absorb heat better than any other mineral and there are a wide varietyof portable diamond testers on the market. Search on Google for "PortableDiamond Tester" and you will find many for sale from $13 to $300. Do NOTbuy a cheap tester -- they are made in China and are not very accurate. Youshould spend around $150 for a good tester.

These diamond testers are hand-held devices with a metal probe that is heldin contact with the suspected diamond. It generates a small amount of heatand measures the speed that the heat is absorbed by the crystal. Good testerscan differentiate between diamond, moissanite (a common syntheticdiamond-simulant), and other minerals.

You do not have to buy a diamond tester. Almost any reputable jeweler willown one, and testing is quick and easy. So try visiting your local jewelerand ask if he will test your suspected diamond.

Conclusion

The odds are against you finding a diamond. But if you are not convinced,first look at the crystal shape to see if it is isometric form, make surethe fracture surfaces are not conchoidal, check if it scratches a corundumcrystal. If it passes all of the above, then try a diamond tester to measurethermal absorption.

One final thought...

The odds of finding a diamond are equal to being struck by lightning on yourbirthday 20 years in a row. Even if you found a real diamond, purchased adiamond tester to verify, nobody will take you seriously. The ONLY way youwill convince anybody it is a real diamond is to have it certified by theGemmological Institute of America (GIA).For a fee they will test your "diamond" and give you a certificate absolutely,positively identifying it as diamond, plus they will give you back the diamondunharmed. With that certificate you will have proof of your find, and buyerswill be seriously interested in purchasing your find.

Because a GIA certificate will eventually be required anyway, save your moneyand do NOT buy a diamond tester. Instead send it straight to the GIA fora certification.

© John Betts - Fine Minerals,New York , NY - All RightsReserved.
a division of allminerals.com, dealerof Fine Minerals since 1989.

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