How to identify a good gemstone?

What could be more tempting than a jewelry display packed with a rainbow of
brightly colored gemstones? Go shopping and you'll see natural, synthetic,
and imitation stones of every color, shape, and size. Can you tell one type
of stone from another? Here are some tips to help you understand the
differences so you can ask the right questions before you buy a colored
gemstone.

Natural stones are courtesy of nature, with no interference from humans.
Don't assume that just because it's natural a stone should carry a high
price tag. Prices are driven by desirability, quality, and availability. A
brilliantly colored ruby with "perfect" clarity will cost thousands of
dollars more than a garnet of similar quality. Become acquainted with the
gemstone market before you buy.

Most natural stones are treated to improve appearance. Heat and radiation
change or enhance colors. Diffusion deepens color, but only within a stone's
outer layers. Oil and waxes are used to fill-in surface-breaking fractures.
Some treatments are permanent--others are not. Treated gems can be a good
choice when you know what you are buying and pay a price that reflects a
stone's true quality.

Unlike diamond gemstone has individual value factors, and within each gem
variety, quality dramatically affects price: a ruby can be worth $10 or
$1,000,000.

First, the basics. Like diamonds, gemstone quality and value are evaluated
according to the "four Cs": color, clarity, cut, and carat weight. For ruby,
sapphire, and to a lesser extent emerald, country or origin also affects
value. Unfortunately, colored gemstones are also commonly treated, so that
also affects value for ruby, sapphire and emerald in particular.

Let's start with the most important gemstone value factors, color, clarity,
and carat weight.

Judging Color - Color is the key factor. But don't 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. Think grass green, not
forest green. Fire engine red, not burgundy. The more bright and vivid the
color, the better.

When a color mixed with gray, white or black we use saturation and hue to
describe the color more deeply.
Saturation means the amount of gray in a color. The gray color has 100%
saturation and 0% saturation mean there are no gray color in a color.

Hue is color perceived to be red, purple, yellow, green etc., and white,
black and gray have no hue.

The tone of a color - Tone means the amount of black or white mixed in a
color. Tone describes as "very light", "light", "medium", "dark" or "very
dark".

Gemstones with high color grades and light-medium to medium-dark tones fetch
the highest prices.
In precise grading terms: clear, medium-tone, intense and saturated primary
colors are the most preferred. Pure blue, not greenish blue. Pure red, not
purplish red. Muted colors and colors between hues, which you might find
very attractive, are usually less expensive. Look at the color in different
kinds of light.

Judging Clarity - The amount or absence of inclusions or other imperfections
within a gemstone determines its clarity. A Clarity grade can be assigned to
a gemstone based on the amount of imperfections, their size, relief
(contrast and appearance), and location within a gemstone. Clarity is one of
the 4Cs used to grade Diamonds in the G.I.A. system of Diamond grading. We
use a clarity grading scale to describe the amount or absence of inclusions
within a gemstone.

clear transparent gemstones with no visible flaws are the most valued. There
is no standardized grading system for clarity: it varies by gem variety.
With colored gemstones, if the inclusion doesn't show in the face up
position, it generally doesn't matter at all. (unlike diamonds which are
graded upside-down at 10x magnification). Some varieties, notably emerald
and red tourmaline, are very rare without inclusions of some kind so the
price structure takes this into account. Pastel colored gemstones show
inclusions more, so they generally detract more from the value for pale
stones.

Carat Weight and Price - Carat is a metric unit of weight used in the
gemstone industry to describe how much a gemstone weighs. A carat is equal
to one fifth of a gram or it can be said that there are five carats in one
gram. The term points means a decimal fraction of a carat. A point is equal
to .01 of a carat. This can equate to one US dollar is equal to $1.00 and it
has 100 pennies or 100 points in one carat.

Gemstones are sold by weight, not by size. Prices are calculated per carat,
which is one-fifth of a gram. Some gems are denser than others so the same
weight stone may be a different size! For example a one-carat emerald is a
bigger than a one-carat ruby. Just like diamonds, the carat weight also
affects the price: large gemstones are more rare, so the price per carat is
higher. But practically, this doesn't make much of a difference with common
gems like amethyst, citrine and blue topaz. It really kicks in for ruby,
emerald, sapphire, alexandrite, tsavorite and demantoid garnet, Paraiba and
rubellite tourmaline, spinel, and pink topaz.

Judging Cut - In my opinion Cutting is in reality the number one item that
you need to be concerned about! Proper cutting is what gives a gemstone its
beauty and brilliance. Many people are confused about what a well cut
gemstone looks like. There are no big mysteries about judging good cutting,
it is very simple. When viewing a gemstone, looking at the table, a well cut
gemstone will be very bright across the entire surface. This brightness is
light being bounced around inside the gemstone and being reflected back to
your eye. You cannot see through a well cut gemstone because almost all
light is being reflected back towards your eyes. Poorly cut gemstones maybe
too shallow or too deep causing what is called a "window". Windows are some
thing that you are meant to look through and these are better left as
windshields in you car or as windows in your home. If you can see through a
gemstone looking from the table down towards the culet, the point on the
bottom, it has a window. If you can see through a gemstone it means that
light is passing through it, along with color and brilliance, it's gone.
Windows weaken the intensity of color and severely affect brilliance.
Gemstones with windows are not desirable, they lack beauty and brilliance.
You want gemstones that have "mirrors" that reflect back to you all of the
beauty and brilliance that is yours to enjoy, but only with well cut
gemstones.

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.

Buy the best within your highest budget!

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!

Different varieties have different price ranges. some varieties are lower in
price because they are readily available, some because the color isn't very
popular, some because the material is relatively soft, some because they are
too rare to create demand and some because no one has heard of them or they
have a weird name. You think I am kidding? Why does tanzanite cost more than
tsavorite or spinel? A pretty name is the only explanation.

Gemstone Treatments - Most gemstones are treated. If you want one, you
basically have to just get over it. Or buy a garnet, peridot, iolite,
spinel, chrysoberyl, or alexandrite, which are basically the only gemstones
that aren't doctored.

Country of Origin - Country of origin matters in the prices of high-end ruby
and sapphire. If a major lab says that a ruby is from Burma or a sapphire is
from Sri Lanka (Ceylon), it costs more than an identical stone without
confirmed origin. Are you buying a gem that is important, say $20,000 or up,
with a certificate? Then you need to think about origin. Burmese and Ceylon
(Sri Lanka) gemstones now command the top prices. If not, don't worry about
it other than the fact that it is kind of cool to know where a gem is from.

What is the best for you?

The Kings of the Gems - ruby emerald and sapphire. Expect to pay between
$250 and $10,000 per carat. Emerald and ruby cost more than sapphire,
particularly in large sizes.

Classics Collection - tanzanite, tourmaline, aquamarine, imperial topaz, and
tsavorite garnet These gemstones are sometimes available in standardized
sizes but fine stones are one of a kind and jewelry will have to be made
specifically for the stone. Prices range between $50 to $1,000 per carat,
with tsavorite easily reaching $3,000 per carat.

Connoisseur Gems - black opal, jadeite, pink topaz, chrysoberyl cat's-eye,
fancy colored sapphires, demantoid garnet and alexandrite. These gems are
sought after and prices range from $250 to $5,000 per carat, although
alexandrite with a good color change will command at least $10,000 even in a
one-carat size.

Collector Stones - spinel, zircon, moonstone, morganite and other beryls,
and many rare gemstones. Collector's gems are not available in quantity to
be marketed effectively so you get a lot of beauty for the money. Red and
hot pink spinels can command a few thousand per carat but most of the gems
in this category will sell for hundreds not thousands.

Affordable Gems - amethyst, white opal, citrine, ametrine, peridot,
rhodolite garnet, blue topaz, iolite, chrome diopside, kunzite, andalusite,
and ornamental gemstones such as lapis lazuli, turquoise, onyx, chrysoprase,
nephrite jade, and amber. These gems combine great color with reasonable
prices and good availability: prices for these gemstone range between $5 and
$100 per carat.