Purchasing and owning of gem stones can be intimidating to the average consumer. In order to help out the consumer, gems are graded based upon their features using the "four C's." These grades rate the gems based upon the rarity of their features, not necessarily the quality. It is important to note that these grades are designed to identify the characteristics of the stones and quality is still based upon preference of the buyer.

Rarity is often what will drive the value of a gem, as the more "unique" the stone, the higher the premium will be. However, rarity is not the be all, end all of gem value. Even with rarity being a factor, a highly desirable stone may still have a high value, regardless of the rarity of characteristics. A good example would be diamonds and engagement rings; a trendy or popular cut may not necessarily be rare, but will still demand a cost premium due to the demand for that particular stone.

The four graded areas are color, clarity, cut and carat.

1. Color is further broken down into three subcategories that further define the color.
* Hue - What is the "simple" color of the gem (green, blue, red, orange, etc.)?
* Saturation - How deep is the color? Is it deep or a light pastel?
* Tone - Is the color light or dark within that particular color's range (dark blue vs. light blue)?

Regarding the effect of color on the value of a stone, it is really only critical in rare or high value gems. An emerald with a perfect green color will be worth more than one that is slightly faded or with a shade of blue. On a moderate or lower valued gem, the color is more of a matter of personal preference.
2. Clarity is the evaluation tool to determine the number of inclusions within the stone. An inclusion is anything in the gem that prevents the clean passage of light through the stone. Some inclusions may be visible to the naked eye, but having a gem without inclusions that you cannot see does not mean that it is free of inclusions. In fact, finding a stone with no inclusions is very rare. Most gemologists will view a stone with a 10x magnifier to determine if there are any inclusions. While not having any visible inclusions is usually preferable, it is important to watch for cracks and chips within the stone that may impact its durability.
3. Cut, the third "C," is the final product and appearance of the stone after it is shaped and cut. A higher grade will be given to cut based upon the appearance of the stone, including how vibrant is it and how well the cut reflects light. For most consumers, cut is a matter of preference and is commonly discussed in engagement rings.
4. Carat is the last grading criteria used on gemstones. Simply put, carat is the size of the stone. From a value perspective, larger gems are going to be worth more than a smaller stone if it has the same cut, clarity and color. Many jewelers determine the price of a stone on a cost per carat basis.

Colors are described by three factors:

* Hue, (red, green, blue, etc.)
* Saturation, (strong or pastel, red or pink.)
* Tone, (light to dark.)

Orangish Red Ruby ... Generally speaking, highest values go to stones with pure hues and strong rich colors. With high value gems, subtle variations make a significant difference in price. For example, a slightly orangish ruby will not be worth nearly as much as one that is pure red. Most people cannot see the difference, but to the expert grader it is significant.
... On moderate priced gems, color has less affect on value. For example, tourmaline comes in every possible color. Unless it is an exceptionally pure green, red or pink, they are all about the same value. It is the other factors of size, clarity and cutting that determine the gem's value.
... Diamonds are graded on how close they are to being colorless. There are three grades of "colorless" that only vary by subtle differences in transparency. Then there are four grades of "white." These are gems that will appear colorless when set in jewelry. It takes an expert in a laboratory setting to distinguish between these grades, but each represents a change in value.
... The color that is best for you is a personal matter. Strong, bold colors correspond with strong personalities; others prefer something softer and brighter. The color of your complexion and the color of the clothing you prefer also have a significant effect on your gem choice.
... To find what colors are best for you, look at a lot of gems. You will find that subtle variations in color can have a significant affect on both how they look on you and your emotional reaction to them.
... If you are a connoisseur of fine gems, the higher grades are significant. On the other hand, the average consumer will find just as much beauty in the more modestly priced stones. Remember, quality does not mean better, it means rarer.

Clarity
... Gemstones contain a wide variety of "inclusions." In a faceted gem, an inclusion is defined as anything that will interfere with the free passage of light. They can be little bits of minerals, hollow areas, or fractures.
... As with color, tiny differences which are only apparent to the grader have a significant affect on value. The best examples of this are diamonds. There are several grades where the inclusions are invisible to the naked eye and have no affect on the beauty of the stone. Yet the difference in value, between something that is very difficult for an expert to find with 10 power magnification and something that is easy to find with magnification, is substantial.
... Most colored stones are simply graded "eye clean," (meaning that the inclusions are not visible to the naked eye,) slightly, moderately, or heavily included. Gems with eye visible inclusions are always lower in value, but the change is not applied equally. There are three classes of colored stones, those that are "usually clean," those that are "usually included," and those that are "almost always included."
Emerald ... Emeralds fall into the last category. Their clarity cannot be compared with other gems. If you want an emerald without any eye visible inclusions, you are limited to small stones. If you want a larger emerald, you will have to accept a certain amount of inclusions and find its value in the color.
... If this does not appeal to you, then look at other green stones, like tourmaline and diopside. Their color can equal that of fine emeralds, without the inclusions, and at a much lower price. Now your choice is between having the name "emerald" or the premium color.
... Eye visible inclusions always have an affect on value. Sometimes this can be used to your advantage. I remember one young woman showing off her engagement ring. She had me look real close to see three tiny black dots. By accepting those small inclusions, which could not be seen from more than six inches away, her fiancé was able to afford a much larger diamond.
Garnet ... You will find just slightly visible inclusions in colored stones as well. Even some stones that are moderately included, like dark garnets, will look fine from the distance jewelry is usually viewed from. It is up to your personality to determine if it is going to affect the joy you get from the stone.
... While beauty is in the eye of the beholder, you need to pay special attention to fractures and veils. They represent a weakness in the gem and are prone to breakage. Earrings, pendants and brooches do not receive much abuse, but ring stones are subjected to a constant onslaught of bumps and bangs. If you intend a gem for a ring stone, you should be particularly cautious of a weak gem.
... Finding these types of inclusions in a gem, and determining their affect on its integrity, is difficult for the lay person to do. The old advice, "If you don't know your gems, know your gemologist," applies here.

Cut
.. The cut of a gemstone, the workmanship that went into fashioning it, is one of the most important factors in its appearance. It is also one of the most difficult factors for the non-professional to judge because of the number of variations involved.
Asymetrical ... The first thing to do is to look at the shape of the stone. Some gems are cut "freeform" but most are intended to be a regular shape. If so, look at the symmetry. Does it bulge here or there, or is it symmetrical in all directions. Look at the stone from the side and the ends. Again, it should be symmetrical in all directions. If not, it is up to you to determine how much it will affect your appreciation of the stone.
Well polished vs. poor polish ... When considering a gem, insist on inspecting it with magnification. Look at areas where light is being reflected from the surface. They should be smooth and mirror like. If you see pitting, scratches, or dull areas, the gem is not well polished. It may look good in the store, but someday you will compare it with a well polished gem and be disappointed with your purchase.
... If it is a faceted gem, look at the facets junctions also. On a well cut stone, they will be crisp and come together in a single point. You may see facets that are slightly rounded and not quite meeting where they should. Just how far off they are will affect the brilliance of the gem.
... The other factors in a faceted gem are too complex for the lay-person. However, you can get a good idea of the cutting quality simply by comparing it with other gems. When you do this, make sure you are comparing similar stones. An amethyst will never have the brilliance of a topaz and dark stones will not be as bright as light colored ones.
Tsavorite Garnets ... When comparing like stones, what you want to look for is the overall light return, the brilliance and sparkle of the gem. It is entirely possible to look at two gems with the same size and coloring, but one having much more brilliance and sparkle than the other. This is the result of cutting.
Windowing ... One thing to pay special attention to is "windowing." That is where light passes straight through the center, rather than being reflected back. It is easy to spot; the center will be much lighter than the outside of the gem and have no flashes of light. Some windows are small; others are quite large and hideous.
... This is another example of something that might look good in the store, but someday you will compare it with a well cut gem and be disappointed with your purchase.
... Cabochons are easier to judge. Begin by checking the polish under magnification. Then hold the stone a short distance from your head and rotate it slowly. Notice how the light passes across the surface. On a well cut gem, it will flow smoothly from one side to the other. If it is poorly shaped the light will not flow smoothly, but snake across the surface. Surface

Carat
... Simply put, larger stones are less common than small ones. Hence, they demand a higher price per carat. For example, a quarter-carat topaz may cost $60 per carat, or $15. A half-carat topaz, (with the same color, clarity and cutting grades,) might cost $100 per carat, or $50. A full carat topaz would cost $200.
... Choosing the right size is a personal matter. For the bold, dynamic individual, a large gem mirrors their personality. On the other hand, small stones are better suited to someone with delicate and feminine tastes. Most people will fall in between these two extremes.
... When budget is a strong factor, smaller stones have a significant advantage. Not only do they cost less per weight, the amount of gem you see is disproportionate to their size. The reason is that volume goes up faster than the outside dimensions. For example, a half carat, round diamond measures 5 mm in diameter, a ¾ carat diamond 6 mm, and a full carat 6.5 mm. From a casual observation, the half and ¾ carat stones, or the ¾ and full carat stones look to be about the same size, but the price difference can be considerable.
... Small gems are often clustered to give the illusion of more gemstone. Seven 1.6 mm diamonds, set close together, will take up as much space as a whole carat diamond. If set on white gold, it is hard to distinguish the separate stones, hence these are often called "illusion settings".
Cluster ring ... While these seven stones approach the eye appeal of a one carat diamond, they only weigh .14 carats. Considering that the price per carat is also much lower, the cost difference is significant. A cluster ring would be in the hundreds of dollars, rather than the thousands.
... Colored stones are often clustered for the same reason: you get a lot more visible gem for less money. If your budget doesn't allow for your first choice in a gem, consider a setting with several smaller gems. With the right piece, you may find just the look and emotional appeal you wanted and at a price you can afford.

GRADE A - Gemstone are graded by color and clarity, most which has been set by the Gemological Institute of America. GRADES or TYPES are used to describe the quality of the stone. Most beads used in handmade jewelry are commercial "GRADE C" beads.

This means they do not have a perfect shape, they have "inclusions" (means "imperfections") that can be seen with the naked eye, and they may have irregular pitting on the surface.

This list will tell you which stones you will find in most handmade jewelry, and what you can expect.
The GIA breaks down colored gemstones into three classes depending upon the likelihood of a particular gem material being "included". For example:

Type I colored stones include Aquamarine, Quartz Crystal, Morganite, smoky quartz, topaz (blue, yellow, orange, pink, red), zircon (blue). In the marketplace these gemstones are often virtually inclusion-free and "eye clear" .

Type II colored stones include corundum (all colors), garnets (all species), iolite, Peridot, quartz (amethyst, citrine, Ametrine), spinel (all colors), tourmaline (blue, orange, yellow), and zircon (green, orange, red, yellow). In the marketplace these gemstones are usually included.

Type III colored stones include emerald, tanzanite, and tourmaline (red, pink, watermelon). In the marketplace these gemstones are almost always included.

When I say I am using GRADE A for a particular piece, it has been graded by an experienced independent gemstone dealer prior to my purchase, and is of EXCELLENT quality, of good color, free of obvious inclusions, and uniform in shape.

GEM QUALITY ( GRADE AAA) is a bead of exceptional quality, rated above and beyond anything you would expect in costume jewelry.

Due to new sources in Hong Kong and India, you will be seeing more and more GEM QUALITY beads here at Gemstonegifts.com.

Heishi - The literal meaning of heishi is "shell" and specifically refers to pieces of shell which have been drilled and ground into beads and then strung into necklaces. More and more frequently, however, heishi (hee-shee) has come to refer to hand-made tiny beads made of any natural material.

Turquoise - The Process Turquoise is synonymous with the Southwest. In streets, plazas and in the middle of the desert; over plain dresses, velvet blouses, satin skirts, cowboy shirts and ceremonial costumes, Anglos as well as Pueblo and Navajo Indians wear turquoise necklaces, turquoise pendant, turquoise bracelets, belts and pins and as much as they can at one time. Elsewhere, turquoise may come and go with fashion. IN the Southwest, turquoise is more precious than gold, an enduring expression of Native American culture. It is the birthstone of December and signifies success.

Sterling Silver: Sterling silver is 92.5% pure silver and 7.5% copper. The copper is necessary for durability and strength since 100% pure silver is too soft to hold up on it's own. Silver is a wonderful neutral color trend these days.

Silver Plate: Silver coating on a base metal, usually electroplated or dipped. It's also a cheaper, yet just as pretty, alternative to sterling silver.

Gold-Fill: Also known as rolled gold, gold-fill products are made by bonding gold with a core of brass. Gold is essentially rolled around the brass core, which explains the term "rolled gold". In the U.S., gold filled items must contain 20% gold by weight. This product has 100 times more gold than a gold plated product, and will last a lifetime if cared for properly. *See Jewelry Care.

Vermeil: Base metal that has been gilded with an overlay of gold.

Swarovski (Austrian) Crystals: Made in Austria, Swarovski products are considered to be one of the finest products of their kind in the world. Unlike Czech glass, these are machine polished and are higher in cost than Czech Glass.

Czech Fire-Polished Glass Beads: Imported from the Czech Republic, these beads are machine faceted, then polished by glazing inside a red-hot oven. This gives them beautiful, glistening colors with a "softer" look and a smoother feel. These are less expensive than Swarovski crystals.

Bali Beads: Bali Beads are hand-crafted in Bali, Indonesia. Each bead is made one by one, they are not cast. They are 92.5% sterling silver, and since each bead is hand-crafted weight may vary slightly.

Pressed Glass: Century-old method of pressing glass into steel molds, resulting in uniform bead shapes.

Diachronic Glass: Vaporized metallic salts are shot through an electronic beam gun onto special glass. It is then heated in a vacuum chamber creating glass with a mystical glowing radiance. Its look is similar to the reflective rainbow sheen that's found in the gas used in vehicles.

Stabilized Turquoise: "Stabilized" turquoise has been impregnated with a clear resin that improves its color and hardness and protects it against fading (color changing) from mild chemicals.

Note: The "Sleeping Beauty" turquoise is the most highly prized turquoise in the world, found in the Sleeping Beauty Mine in Arizona. This bright, vivid blue turquoise, often referred to as "Persian color" is bright, vivid blue and most pieces are perfectly clear of any inclusions (dark markings or veins).

Cat's Eye Beads: Top "A" grade fiber optic glass beads should be expertly shaped with a well-defined "eye" line and uniform "eye" within the bead strand. This kind of bead has graduated colors in it starting with a lighter colored "eye" centered around the middle of the bead, much like the Tiger Eye stone.

Aurora Borealis Finish: A rainbow finish added to the outside of glass beads after polishing. It's long lasting and doesn't fade or chip with normal wear.

Grading Brilliance/Internal Luster
Brilliance aka Internal Luster is an often neglected factor in colored gem grading, yet is probably the single most important element.

Besides being a significant contributor to a gem's beauty and appeal. Observing flashes of brilliance is extremely important.

For in those flashes of brilliance we see the true hue, tone and saturation .. and even get a strong clue about clarity.

Procedure

* Hold the gem with tweezers and about 45 degrees to the light path
* If the gem is not round, only half will normally show brilliancy in the illustrated orientation
* First observe the lower half[Item 1] on [a] half of the gem
* Rock the gem a few degrees to get the best play of brilliance
* Note: When moved, the brilliancy flashes will seem to trade places with similar areas of extinction
* Mentally estimate the total area of brilliance and extinction as a percentage for that half of the gem
* Caution: Don't rock the gem more than about 15% or the entire gem will appear washed out
* Exclude any areas of the gem (table and crown) that never show brilliance
* Rotate the gem 180 degrees and repeat the procedure [Item 2] on [b] that is now the lower portion of the gem
* Rock the gem to get the maximum brilliance
* Estimate the percentage for that half of the gem
* Average the two percentages to get a total percentage of brilliancy

Round gems are easier to grade for brilliance. One observation is normally sufficient to establish a percentage of brilliance.

If 100% of the gem shows brilliancy in both positions when rocked it is considered 100% brilliant

Note: A gem can never show 100% brilliancy in all areas at the same time

Other things that observing brilliance can tell us

* Fuzziness - heavily included gems can diffuse the transmission of light
* Dead areas - due to the masking of light transmission
* Dimness - limited transparency
* Weakness of points of brilliance - in a clean stone usually indicates a poorly proportioned gem
* Imbalance - in the areas of brilliance in a clean stone normally indicates poor symmetry

Grading points

* 10% = 1, 20% = 2, 30% = 3, 40% = 4, 50% = 5, 60% = 6, 70% = 7, 80% = 8, 90% = 9, 100% = 10
* Deduct 1 if the brilliancy areas are not crisp
* Deduct 1 if the brilliancy areas are unbalanced