Quality And Value Of Gemstones

Becoming an educated consumer is not such an easy matter when dealing with all the variables related to the purchase of a colored gemstone. These many variables will determine the quality, therefore the price. In general, the quality and value of a gemstone is determined by a combination of what are called the "Five C's":       "what?... I though they were "Four Cs" ...well, see why five.
Clarity (degree of flawlessness), Color, Cut, Carat weight and fair Cost.
We believe that Treatments also should be added to the list, as they play a very important role in today's evaluation of quality and price. If a stone is left untreated, in a nowadays market filled with treatments of all sorts, the stone acquires additional, in most cases substantial value over a stone that has been treated. 

Clarity is the degree of flawlessness. As a general rule, a clear transparent gemstones with no visible flaws is the most valued.
GIA (Gemological Institute of America) classifies colored gems clarity of three types:
Type 1 gemstones,  "virtually inclusion-free" such as aquamarine, topaz, green tourmaline, tanzanite, citrine, damburite.
Type 2 gemstones,  "usually included" such as rubies, sapphires, garnets, peridots, amethysts, zircons, cat's eye chrysoberyls, pearls, corals.
Type 3 gemstones,  almost "always included", such as emeralds and red tourmalines.
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 the so called "cat's eye" and the "star" in the star sapphire. Inclusions can also be a birthmark, telling us where a particular gemstone was mined.
Let's talk about sapphire and ruby clarity. Since they are type2 gems, both the sapphire and the ruby are generally "usually included" gems. As a general rule, look for eye clean stones. If the inclusions are too numerous, too visible to the naked eye and/or distracting, avoid such stones. However, there is an exception to the rule. The exception is what is called "gem quality" gem. A gem quality stone is a specimen that has top, finest color and a conspicuous carat weight. In a gem quality piece, a certain degree of inclusions are accepted and do not diminish the value of the stone.

Color is another key factor. A common misperception in judging gems is that 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 light. Sometimes, in daylight, a gem shows one color and in artificial light another one. This color change gems are usually very attractive and in most case expensive. (alexandrite is the most well known example, but sapphires, garnets, spinels can also change color).

It use to be that a good Cut was something that did not cost more. Nowadays, a savvy consumer knows that a well cut gemstone can add or subtract a lot of beauty. And beauty, in the end, is what we pay in a gemstone. 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 a bit darker. If it is too shallow and wide, parts of the stone will be washed out and lifeless (the so-called window). The best way to judge cut is to look at similar gemstones next to each other.