What do you check for when buying a quality gemstone? What is a good quality gemstone? These are questions I am asked frequently.
As today is #qualityday, it seems an ideal time to recap what to look for when buying a quality gemstone. It’s true that beauty is the eye of the beholder, but over the years many thousands of beholders have decided what matters when it comes to a gemstone’s value on the open market.
There’s an easy way to remember what makes up the elements of a quality gemstone—the Four Cs, which stand for Colour, Clarity, Cut and Carat weight. The Four Cs are what the G.I.A.’s expert gemmologists use when assessing diamonds, though they are used with caveats when appraising other gemstones, too.
Usually, the value of a gemstone come down to an interplay between these factors, with some outweighing others in different circumstances. We also need to factor in a gemstone’s origin and treatment. Even if they can sometimes be a blunt tool in the hands of an inexperienced buyer, knowing about the Four Cs can provide consumers with a decent rule of thumb.
The Four Cs were a mnemonic invented in the 1940s by G.I.A founder, Robert Shipley, who wanted to help his students remember the important characteristics to consider when evaluating a diamond. Before Shipley, diamond merchants used several different terms to refer to the colour, clarity and cut of a gemstone. Carat weight was the only one of the Cs to have been used consistently. Indeed, records show that it dates back to around the 1500s.
What was so revolutionary about the Four Cs was that they provided the gemstone trade with an industry standard. Testing results were now repeatable and verifiable.
The Four Cs don’t always fit so easily when appraising other gemstones, of course, and many tend have their own set of quality guidelines—for example, pearl is never faceted and so ‘cut’ does not apply. Likewise, clarity isn’t always appropriate when it comes to opaque gemstones, when uniformity of colour is often a more valid consideration.
Interested to learn more about buying a quality gemstone? Take a look at the Gemstone Detective travel guide series to buying gemstones and jewellery around the world!
Kim Rix, GG GIA
Be sure. Be smart. Buy with confidence