Like diamonds, the value of colored gemstones,depends largely on "the 4 C's".
Those are Color, Cut, Clarity, and Carets.
Unlike diamonds, the value of a colored gemstone is effected most by the color.
Color is judged by three criteria: Hue, Saturation and Tone.
Generally, stones with strong, pure hues are are more valuable.
For instance a slightly orangish-red Ruby will be much less valuable than a stone that is pure red.
Saturation refers to the intensity of the color.
Highly saturated colors are very vivid.
Less saturated colors tend to be more grayish or brownish.
Tone refers to how light or dark a gemstone's color is.
For example, pink would be a light tone of red.
Stones with a very dark tone will be almost black.
The standards are different for different types of stones, but generally the best stones are ones with pure hues, vivid colors and moderate saturation (not too dark or too light).
Clarity takes into account the inclusions in the gemstone.
Inclusions are spots, fractures, imperfections, or anything that interferes with the passage of light through the stone.
The spots can be small crystals of other minerals or sometimes tiny droplets of water or gas trapped within the stone.
Generally, a stone with fewer inclusions is more valuable.
Virtually all stones have some inclusions.
Some varieties tend to have more than others and so inclusions are more acceptable in some stones.
The best example of this is Emeralds.
They almost always have visible inclusions and so their value won't be effected as much by inclusions as would an Amethyst, for instance.
That is because there is a lot of very "clean" Amethyst available.
The Gemological Institute of America has classified all common gemstones into 3 types, based on how included they tend to be, and defined standard clarity grades for each type.
You can see their Clarity Grade Chart here: http://www.
palmbeachgems.
com/Gemstone_Information.
htm#Grading Cut refers to how well the stone is faceted.
It should be well proportioned, and symmetrical.
The facet junctions (where the facets meet) shouldbe crisp and come together in a single point.
The surface should be smooth and well polished.
The quality and the craftsmanship of the cut has a profound effect on the overall beauty of a gem and so has a significant impact on its value.
A well cut stone will have more brilliance and sparkle than a poorly cut gem.
Although, keep in mind that a stone can be re-cut.
In some cases it is worth the expense and the loss of some caret weight to re-cut an otherwise fine gem.
"Caret" refers to the weight of the stone.
Obviously a bigger stone is worth more than a smaller stone of the same quality.
With some varieties of gems, a larger stone will be much more valuable "per caret" than a smaller one, because larger sizes are much more rare.
This is the case with sapphires.
A3 caret sapphire will be worth a lot more than Twelve 1/4 ct.
sapphires.
In other cases, like Citrine, where large sizes are readily available, the price per caret will be about the same, or may even be less for the larger stone.
These are the basic criteria used to evaluate colored gemstones.
Obviously this is a complex subject.
Continue to learn more about each of the terms and topics mentioned here and look at a lot of gemstones and before long you will be able to easily separate the quality stones from the less desirable.
Combine this with a knowledge of prices and market conditions and you will be able to recognize a good deal when you encounter one.
Those are Color, Cut, Clarity, and Carets.
Unlike diamonds, the value of a colored gemstone is effected most by the color.
Color is judged by three criteria: Hue, Saturation and Tone.
Generally, stones with strong, pure hues are are more valuable.
For instance a slightly orangish-red Ruby will be much less valuable than a stone that is pure red.
Saturation refers to the intensity of the color.
Highly saturated colors are very vivid.
Less saturated colors tend to be more grayish or brownish.
Tone refers to how light or dark a gemstone's color is.
For example, pink would be a light tone of red.
Stones with a very dark tone will be almost black.
The standards are different for different types of stones, but generally the best stones are ones with pure hues, vivid colors and moderate saturation (not too dark or too light).
Clarity takes into account the inclusions in the gemstone.
Inclusions are spots, fractures, imperfections, or anything that interferes with the passage of light through the stone.
The spots can be small crystals of other minerals or sometimes tiny droplets of water or gas trapped within the stone.
Generally, a stone with fewer inclusions is more valuable.
Virtually all stones have some inclusions.
Some varieties tend to have more than others and so inclusions are more acceptable in some stones.
The best example of this is Emeralds.
They almost always have visible inclusions and so their value won't be effected as much by inclusions as would an Amethyst, for instance.
That is because there is a lot of very "clean" Amethyst available.
The Gemological Institute of America has classified all common gemstones into 3 types, based on how included they tend to be, and defined standard clarity grades for each type.
You can see their Clarity Grade Chart here: http://www.
palmbeachgems.
com/Gemstone_Information.
htm#Grading Cut refers to how well the stone is faceted.
It should be well proportioned, and symmetrical.
The facet junctions (where the facets meet) shouldbe crisp and come together in a single point.
The surface should be smooth and well polished.
The quality and the craftsmanship of the cut has a profound effect on the overall beauty of a gem and so has a significant impact on its value.
A well cut stone will have more brilliance and sparkle than a poorly cut gem.
Although, keep in mind that a stone can be re-cut.
In some cases it is worth the expense and the loss of some caret weight to re-cut an otherwise fine gem.
"Caret" refers to the weight of the stone.
Obviously a bigger stone is worth more than a smaller stone of the same quality.
With some varieties of gems, a larger stone will be much more valuable "per caret" than a smaller one, because larger sizes are much more rare.
This is the case with sapphires.
A3 caret sapphire will be worth a lot more than Twelve 1/4 ct.
sapphires.
In other cases, like Citrine, where large sizes are readily available, the price per caret will be about the same, or may even be less for the larger stone.
These are the basic criteria used to evaluate colored gemstones.
Obviously this is a complex subject.
Continue to learn more about each of the terms and topics mentioned here and look at a lot of gemstones and before long you will be able to easily separate the quality stones from the less desirable.
Combine this with a knowledge of prices and market conditions and you will be able to recognize a good deal when you encounter one.