Appraising the Value of Gems

Appraising the Value of Gems

by Mathew Abraham

Gems are appraised mainly to determine their fair market value (FMV) or for insurance purposes. Qualified gemologists undergo specialized training to be certified as accredited appraisers of gems. If a gem has been certified by a Master Gemologist Appraiser, his/her valuation is accepted as final.

The Need for Having Gems Appraised

The techniques for manufacturing imitation costume (or artificial) jewelry have been developed to a level where it is almost impossible for an average person to differentiate between them and the originals. Add to this the fact that some jewelry retailers ridiculously inflate the price of genuine precious stones and you can see why it is necessary to have your gems appraised and certified at the time of purchase. After spending a tidy amount on a gem you have just acquired, the last thing you would want is to find that your friend has purchased an identical stone for a much lower price, or that your stone is of inferior quality! There is no ready market for the resale of gems so you need to get professional advice and analyze the various gems and their characteristics before deciding what to buy. Whether it is for your collection, an investment for resale, or as a gift, get your gems appraised for insurance purposes as well as for knowing their fair market value.

Grading and Appraising Gems

There are a standard set of rules to be observed in the purchase of any gem, followed by separate rules for each variety of gems. While the system for grading and valuing diamonds is well established and dependable because of steady market conditions and stable supply and demand, the same cannot be said for most other gems, especially when supply and demand are unpredictable. While most gemologists can prepare a grading or identification repot on a stone, only an appraiser can give its exact value. Most appraisers include a grading report also. Some jewelers subject inferior quality colored gems to enhancement – like heat treatment, irradiation or oiling – to get a better price for them and a good appraiser will be quick to notice such embellishments. Some stones have a high value because of the history or folklore attached to them. Stones coming naturally in identical pairs or suites fetch a comparatively better value than a single stone of the same quality.

What does an Appraiser do?

The term ‘appraising’ refers to the process of evaluating a product on the basis of specific criteria and for specific purposes. Gems are appraised mainly to determine their fair market value (FMV) or for insurance purposes. Qualified gemologists undergo specialized training to be certified as accredited appraisers of gems. If a gem has been certified by a Master Gemologist Appraiser, his/her valuation is accepted as final. These appraisers need to have their credentials revalidated every five years. They need to update themselves with the latest developments in the field of gemology. Appraisers may specialize in evaluating different kinds of gems and jewelry. They are even given special courses in market research and analysis for gems.

Appraisers make a detailed study of the various characteristics of gems. The chemical composition is analyzed to determine if it is essentially a chemical element, a simple chemical compound, or a complex compound of chemicals and elements. The crystal structure is analyzed to determine whether they are crystalline, non-crystalline or organic. The crystal structure can be cubic, hexagonal, tetragonal, orthorhombic, monoclinic or triclinic. Gems are studied for their optical effect. Besides assessing the color, they are analyzed for factors like optic character, refractive index, birefringence, dispersion, fluorescence, phosphorescence and clarity of color. Some gems display rare special optical effects called ‘phenomena’, which enhance the attractiveness and value of the stone. These gems are studied for chatoyancy, asterism, iridescence and aventurescence. Each gem is assessed for specific gravity or relative density. Durability of the stone is assessed to determine hardness and toughness. Thermal conductivity is assessed as the ability to conduct heat varies from stone to stone.

A variety of appliances and accessories are used in the process of appraising a gem. These include binocular microscopes, refractometers, polariscopes, Chelsea filter, aka emerald filter, spectroscope, ultraviolet light source, special specific gravity testing liquids, X-ray photographs, etc.

The Final Analysis

Generally gems are categorized as Precious stones – diamonds, rubies, emeralds, sapphires, opals and pearls – and Semi-Precious stones – most other colored gems. But this classification is rather ambiguous as inferior quality ‘precious stones’ are much cheaper than top quality ‘semi-precious stones’. Even the general differentiation between diamonds and ‘colored stones’ is inappropriate, as some diamonds are colored and some ‘colored’ stones have no color. Some unusual gems are further classified as Museum Grade stones and Rare or Collector stones.

The basic principle of the 5 Cs is applied for all gems – Cost should be determined by Carat, Cut, Clarity and Color.

The price per carat does not rise proportionately but exponentially. This is because large gems are difficult to come by. While larger carat weights naturally attract higher prices, the stones should be of a size suitable for ornaments to have value.

A gem must be strikingly beautiful in appearance to have real value. Sparkle and color are the primary considerations and should be evident even from several yards away. Cut and clarity determine the impact of sparkle and color. The pattern of cutting differs for diamonds and colored stones, as the optical properties of the latter are variable. Different types of cuts include heart, octagon, pear, marquise, round brilliant, oval, square, trilliant, round cabochon, princess, antique cushion, baguette, emerald cut, and briolette. Good diamonds should be dazzling with their white fire and good colored stones should maintain the richness of their color in daylight as well as indoor conditions. A really good gem will stand out anywhere, anytime!

Some persons claim they can asses a stone with just one careful look. They may or may not be correct in their assessment, but, when you consider the professional competence of a certified appraiser, it is much better to be certain than to take a risk when investing your valuable money in gems. Certified gems are far more valuable whether they are for resale or for a collection. It is a good practice to have precious stones appraised and revalued periodically, so that you can always rest assured that you know the exact value of your collection.

Interest Items: