Diamond Art Deco Engagement Ring

8 Things You Need to Know About Buying Gemstones/Jewelry

Blog post originally appeared on Jenny Andersen’s blog 8/10/19

1.         The Four Cs for buying diamonds are pretty well known by now, but just in case you missed the memo:

Carat    Size of the diamond by weight. Here’s a link to a great chart showing what different cuts and sizes look like: size chart. Just remember that size isn’t everything! Some people prefer a smaller, more sparkly (yeah, technical term) stone to a larger, duller one.

Color   Ideally, white diamonds are colorless. This is measured by GIA (Gemological Institute of America) on a scale of D to Z, D being colorless. Most people don’t detect faint amounts of color in a stone; the usual threshold of visibility is around K to L. Fancy Color diamonds are another matter.  The more color the better!

Cut       The amount of sparkle a cut stone has depends on the cut. Angles between facets and precise alignment of facet junctions can best be judged by a gemologist. Note that older/less modern cuts can be very charming, and really sparkly, especially in candlelight.

Clarity  Inclusions, cracks, feathers, the list goes on. If you can see stuff (another technical term) with your naked eye, you may want to move on to a better stone. Clarity is graded from Flawless (and really expensive) down to I3, which means not only can you see the problems, but they affect the integrity of the stone.

2.         Size matters. Some sizes are more popular and are priced accordingly, especially for diamonds.  For example, a one carat stone may cost more per carat than a stone that weighs 0.89 or 1.21 carats. (Numbers selected at random to illustrate smaller or larger.)

3.         These days, many—most?—stones on the market are treated in some way. It’s good to know what the treatment was, but that doesn’t necessarily mean you shouldn’t buy.  Reputable jewelers reveal treatments.

4.         To look more knowledgeable, hold a jeweler’s loupe, that funny little magnifier, close to your eye and move the stone closer until it’s in focus.

5.         ‘Peridot’ is pronounced ‘PERidoh’. Chalcedony is pronounced ’kalSEdony’.

6.         Identifying a stone by color is not reliable.

7.         The ‘big’ precious stones are diamond, ruby, emerald, and sapphire. Semiprecious stones are often gorgeous and much easier on the pocketbook. (Mostly.)

8.         Don’t try to fake knowledge you don’t have!