Value factors: Color,
Clarity, Cut and Carat Weight
Gemstone quality and value
are evaluated according to the "4 Cs": color, clarity, cut, and carat
Color is the key factor. A
common misperception in judging gems is people assume that the darker
the color, the better the stone. That isn't true: color can be too
dark, like some sapphires that look more black than blue. If a gem's
color is too dark, it is subdued and lifeless. A much better rule of
thumb is the brighter and more rich and vivid the color the better. In
general, within each gemstone variety, a clear, medium-tone, very
intense and saturated primary color is the most preferred. Muted
colors or colors between hues, which you might find very attractive,
are usually less expensive. Look at the color in different kinds of
The next most important
factor affecting value is clarity, with clear transparent gemstones
with no visible flaws being the most valued. Some gemstone varieties,
notably emerald and red tourmaline, are very rare without inclusions
of some kind so the price structure takes this into account.
Some gemstones are valued
for their inclusions! Phenomenal gemstones owe their stars and eyes to
inclusions. Tiny inclusions reflecting back light put the eye in
cat's-eye chrysoberyl and the star in star sapphire. Inclusions can
also be a birthmark, telling us where a particular gemstone was mined.
A good cut is something that
may not cost more but can add or subtract a lot of beauty. A well-cut
faceted gemstone reflects light back evenly across its surface area when
held face up. If the stone is too deep and narrow, areas will be dark.
If it is too shallow and wide, parts of the stone will be washed out and
lifeless. The best way to judge cut is to look at similar gemstones next
to each other. Ask your jeweler to show you a well-cut gemstone.
Gemstones are generally sold
by weight not by size. The price will be per carat, which is one-fifth
of a gram. Some gems are heavier than others so the same weight stone
may be a different size! The carat weight also affects the price: large
gemstones are more rare, so the price per carat is higher.
In general, gemstone pricing within each variety follows common sense:
the more beautiful the gemstone, with the final visual effect of all the
quality factors, the more valuable it is. Don't be afraid to choose what
looks best to you!