Five C Color Color is the number one factor in determining the value of any gemstone. The more intense the color is the more value it has. An example would be the very dark blue sapphires that are offered by some dealers, sometimes they are called navy blue. These navy blue sapphires go almost black when taken out of the strong lights and this is how you will normally see these gems because you do not walk around with a high intensity light to show others your item of jewelry. Gemstones that look great under a dealers strong lights should also be seen with these lights turned off to see the real color that you will see daily under normal conditions. If the gemstone goes too dark of a color with the lights off you need to pass on this gem and select another. Carat Weight 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. 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. Clarity Clarity is the term used to describe how clean a gemstone is using a monochromatic color corrected 10X magnification. The Gemological Institute of America (GIA) has set forth standards for clarity grading of Colored Gemstones and Diamond. Confidence Confidence is an additional quality that I have added here. You need to have confidence and trust with those whom you are dealing with. Ask questions and expect answers to your questions regarding a dealers expertise in gemstones or ethics. Is the dealer reputable and knowledgeable? Is the dealer familiar with the AGTA Gemstone Enhancement Codes and do they use them? Did you know that gemstone enhancement disclosure is required on all invoices, memorandums and advertising by the Federal Trade Commission? What type of return policy does the dealer offer if there is a problem? Can the dealer show you a range of items to select from and explain what the differences are and why the price differences? Are you dealing with a sales person or someone who knows what they are doing?

Gems & Treatments -

Oiling

This method has been used for more than 600 years, mostly on fissured and porous gemstones - especially Emerald. This treatment reduces brittle fractures and may provide a better clarity. Besides colorless oils various fillers are used, e.g. wax and natural or synthetic resins. Oiling is not a permanent treatment and in some cases requires reapplication every few years, but it is generally accepted. Special care should be exercised when mounting, repairing and cleaning oiled gems. Under no circumstances oil-dissolving chemicals should be used for cleaning.

Heating

To heat most kinds of colored gemstones is a standard procedure between mining and cutting of the gem. It became more and more sophisticated as the knowledge about it was passed over from generation to generation. Methods vary from simply burning the rough minerals in an open fire to highly elaborate techniques under regulated temperatures.

Why are gemstones heated?

The rough gems are heated to improve their quality. Through burning, as the heating is also called, hues become stronger, colors are revealed or even changed by the process, inclusions become less prominent or vanish at all, and the durability of the stone is improving. For example, if a darkish Tourmaline is heated, its color will brighten. Heating can lead to astonishing outcomes, and otherwise unimposing minerals are turned into beautiful sparkling treasures. In today markets, you will find that Aquamarine, Amethyst, Citrine, Kunzite, Tanzanite, Topaz, Tourmaline, Zircon as well as Ruby and Sapphire are enhanced with heat in most cases.

Does heating effect the price of a gemstone?

The good quality gemstones are by far less common than comparable enhanced ones, and this can be reflected in the price. Unheated Red Ruby and unheated Blue Sapphire are in permanent demand, and those natural wonders are traded with a premium. Top quality unheated Red Ruby and Blue Sapphire are absolutely rare, hard to find even in the world's most famous deposits and therefore extremely expensive. On the other hand, many kinds of gemstones would not exist without heat treatment, e.g. tanzanite or prasiolith. Some gems are demanded at large amount in colors that they would not have if they were unheated. So in general, heating does not necessarily decrease the value of a colored stone, while it sometimes even increases its value.

Heated gemstones do not require a special care. The treatment is permanent and accepted within the gem community. Heating does not change the chemical structure of the gem

Beryllium Heating

Beryllium heating is most commonly used to reveal yellow and orange colors in sapphires. Sapphire is often found in gem gravels together with Spinel, Tourmaline and Chrysoberyl. Latter has an influence to the color of the Sapphires if heated together: To sort out the different specimen before the traditional burning process is sometimes too difficult. Heated together, the Chrysoberyl (BeAl2O4) volatilizes very little quantities of Beryllium (Be). This is probably a catalyst causing a thermo-chemical reaction in the Corundum's atomic structure. Once this coherence was found, it was made a point to produce Yellow and Orange Sapphire. The exact coloring process in this reaction is still unknown. The method is relatively new, hence it is also frequently called “new heating” or “heat treatment with additives”. Beryllium heating cannot be detected by standard gemological analyzing methods, only by two sophisticated and expensive tests which both are destructive.

Diffusion

Diffusion or “surface diffusion” is an enhancement method in which certain elements such as iron and titanium are added during the heating of the gemstone. Commonly used on Corundum, the added elements create a diffusion layer. This layer can be a colored coating or contain asterism producing inclusions, or both. This treatment is quite stable, but surface Diffused Star Sapphires or Diffused Sapphires should be handled with special care because the effect bearing subsurface is only about 0.1mm in depth. A diffused gem may lose its beauty if scratched, polished, re-cut, or otherwise damaged.

Irradiation

Hidden in the depth of Earth for millions of years, gems are undergone to natural radiation that can impinge on the colors or clarity of gemstones. If exposed to artificial gamma or electron irradiation, this effect can be used to enhance the gems. Within hours, a gemstone's color can be altered and the clarity improved. Irradiated gems do not require special care and the treatment is considered permanent, but the colors may fade with time or regress towards its previous hue in some cases (Yellow Beryl, Kunzite, Blue Topaz).

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