How Do Jewelers Rate Diamonds?

We began our search by entering "diamonduses a small light, such as the one that comes
ratings" into the search box. The results led us towith your key ring. If you shine the light through
online gift retailers, where we quickly found athe stone and cannot see it on the other side, but
useful page on on the "4 C's" of diamondonly a bright halo around the rim, it is more likely
evaluation: color, clarity, cut, and carat.to be a true diamond.
From that document, we got the sense that theDiamonds are also very good at conducting heat.
most reputable ratings are performed byBreathe on the surface of the stone and
independent laboratories such as the Gemologicalimmediately check to see if it has fogged up.
Institute of America (GIA) and the EuropeanAgain, quartz, glass, and cubic zirconium will stay
Gemological Laboratory (EGL). We returned tohazy for a moment before the condensation
search engines and searched on the names ofdissipates, but you shouldn't be able to see any
these groups. We found both listed under themoisture on a true diamond. However, one rock,
Gemology - Organizations category.called moissanite, will also pass this test, so the
A visit to the Gemological Institute of Americabest way is to get a complete thermal
site left us a little disappointed. They seemed toconductivity evaluation performed by a jeweler.
offer a great deal of information on their courseLooking closely at the specks, ridges, and facets
offerings, but little in the way of referencecan also give you a clue into the identity of your
material.gem. Diamonds do have inclusions, tiny bits of
The EGL site was also underwhelming. Still, if youother minerals that got crushed into the diamond
find yourself coming across EGL or GIA reports inwhile it formed deep under the earth. However, if
the course of your diamond hunting, it's probablythe facets have worn or rounded edges, bubbles,
a good idea to familiarize yourself with theseor if the gem looks rippled or pitted, it is probably
organizations.glass. Those gems that are perfectly clear, with
Ultimately unsatisfied with the results of ourabsolutely no inclusions, are probably quartz.
search, we decided to browse more. Happily,Finally, some common sense measures can
before long we found a nice site that offersprevent you from getting pressured to purchase
information on the 5 C's (they added "cost"),a gem that turns out to be something other than
diamond shapes, "How to Buy a Diamond," anda diamond. It shouldn't be ridiculously inexpensive,
"How to Read a Diamond Certificate."or you'll get what you pay for. It also will usually
The only people who can authenticate a realbe mounted in an "open back" setting, which
diamond are certified gemologists specializing inmeans that you can see around the rear of the
jewelry. However, if you are browsing rings at agem and the back surface isn't coated with any
flea market and want to quickly assess whethersilvery substance. Although it's true that diamonds
a clear stone is probably glass, cubic zirconium,are the hardest organic substance on earth, the
quartz, or leaded crystal, there are a few easyinfamous test of scratching diamonds across glass
tests you can apply without any specialor metal might just give you a damaged diamond.
equipment. These tests at least rule outEven many gemologists cannot distinguish "real"
recognizable imposters because they rely on thediamonds from cultured diamonds. Cultured
way a real diamond stone refracts light, conductsdiamonds have been artificially manmade in a
heat, and looks up-close.laboratory, not mined from mountains, yet they
If the gem in question is loose and unmounted,are chemically identical to those diamonds. Some
try placing it over printing. Diamonds refract socompanies are developing new kinds of
much light that they will not work as a magnifyingidentification methods for those who would like to
glass and you would see no lines, circles, or letterspurchase a mined diamond or for those that
through them. Other clear stones like glass orprefer a cultured one.
crystal will reveal the print clearly. A similar test