The basic factors that contribute to the value of a gemstone are BEAUTY (color, luster, perfection of cutting, etc.) DURABILITY, RARITY, DEMAND (or VOGUE), TRADITION, and PORTABILITY.
BeautyUnless a gem material possesses BEAUTY, it cannot be considered as a gemstone, thus industrial diamonds and oyster concretions, which do not have a pearly luster, have no value as gemstones and cannot be considered gems. A transparent colored stone, such as ruby, depends for its beauty on several factors namely: the quality and depth of color, the degree of transparency, and fashioning. An opaque stone depends for beauty mainly on color and, to a lesser extent, on fashioning. Frequently, laymen consider some materials to have no significant beauty, but they suspect that it is a gem mineral and therefore assume that it must be valuable. It cannot be overstressed that beauty is a prerequisite for gems. Obviously, a specimen that will not yield a beautiful cut stone cannot have any gemological value. Whenever a concretion is found in an oyster, the average person regards it as a pearl and assumes it is valuable. Actually, edible oysters are not capable of producing the nacreous layers that give the true gem pearl its color and luster, therefore, such pearl like formations are not true pearls and have no value. If these specimens possessed any degree of beauty it would be a different matter, however, they always have a dull, "lifeless" luster.
It is not necessary that a specimen display its maximum beauty in order to be valuable. For example, a fine quality rough specimen of ruby with highly abraded surfaces might be very unattractive to the layman but have great potential beauty that could be revealed by proper fashioning. Thus, to quality as a gem or gem mineral, a specimen must display beauty or possess potential beauty that can be revealed by fashioning.
DurabilityAnother essential requirement for a gem is DURABILITY. This does not mean that it should be indestructible; no such material exists. To be of use as a personal ornament, a stone must simply resist ordinary wear sufficiently well to retain its luster for a reasonable period, In other words, its beauty must be of a lasting nature when given reasonable care.
One outstanding characteristic of gems is chemical and structural STABILITY. Unlike some metals that oxidize and slowly disintegrate, or some fabrics and woods that decompose, gems will withstand for centuries conditions that quickly destroy most other materials. In this sense they are exceptionally durable.
Although all of the important gems in fine quality are relatively durable when compared with other materials, there are' extreme differences between various gem species; for example, diamond and opal. Al though capable of producing beautiful cut stones, some mineral species are so soft and lacking in toughness that they fail to quality as gems. The mineral sphalerite is a good example, because beautiful stones may be cut from transparent pieces but they are so fragile that they can be damaged with the fingernail. A similar example, the satinspar variety of gypsum, is so low in hardness that the exceedingly lovely cat’s-eyes that may be cut from it are suitable only for display purposes. But by definition, then, gemstones are necessarily limited to the harder minerals.
RarityThe third factor contributing to the value of a gemstone is RARITY. Rarity frequently plays a very important role in determining the value of a gemstone, since, obviously, the rarer the material in great demand as a gemstone, the higher its value. Consequently some minerals are very common in nature but are sufficiently lovely to be in demand. The greater availability of average qualities results in lower mining and handling costs; thus the price is consistently low. Such a gemstone is amethyst. In its finest quality it is a lovely stone indeed, yet its price to the jeweler rarely exceeds $10 per carat. This is because even fine quality material is not rare compared with more expensive gemstones. On the other hand, even medium quality emerald is very rare when compared with amethyst. As a result, per carat cost of a very fine emerald may exceed $2000 to the jeweler. Not only is the lovely green of emerald highly cherished, but its great rarity makes demand very high in relation to availability. The same holds true, of course, for fine rubies, cat's-eyes, star rubies and star sapphires. The finest qualities of ruby and emerald are more valuable per carat than colorless diamonds of comparable size and quality.
It is interesting to note that a gem material or potential gem material may sometimes be too rare to be in demand. Unless it is common enough to be known to many people, too little demand exists for it to achieve sufficient status to bring high prices.
Such materials are benitoite, a lovely sapphire-blue gemstone, and euclase, some varieties of which resemble the finest aquamarine.
DemandThe fourth factor having a bearing on the value of gemstones is DEMAND, or VOGUE. There are times when some of the less important gemstones enjoy great demand and other times when they are in relative eclipse. In the twenties, for example, amber was highly promoted and a great demand for it was created. It soon represented the second most important gem importation into this country in terms of gross value , The fad did not last long, however ,and at the present time amber is rarely seen in jewelry stores.
Interestingly enough, after the introduction of Linde star rubies and star sapphires, particularly the inexpensive qualities of natural star sapphires became exceedingly popular, and prices have been higher than they were before the introduction of the Linde product. The great amount of publicity given to Linde’ s development, plus their continued advertising program, has created widespread interest in star stones. Once the interest, or demand, was created, it applied to all asteriated stones, both synthetic and natural. This offers concrete proof of the unrealized potential in colored stones.
From time to time, fashion dictates the use of very large stones or numerous small stone's massed in settings. Factors such as these have a bearing on value at that time.
TraditionOne of the most important factors affecting the demand and value of gemstones is TRADITION. It might be said that tradition, as applied to gems, is the sum total of all the effort throughout the centuries to interest and educate the public in the use of gems for ornamentation, symbolism, and as a medium of exchange. Such effort includes the deliberate promotions on the part of jewelers, the publicized purchases and subsequent use of gems by royalty and wealthy individuals, the use of gems for symbolization in various churches and other developments in which gems play a part. All of these activities have, over a period of time I created an acknowledgement by the public of the importance of gems.
Demand follows acknowledgement and is spurred on by rarity. It is human nature to want the things we cannot have or those that are difficult to obtain, particularly if ownership gains recognition of achievement. If beauty alone were the only sought-for quality in jewelry and-gems, then imitations, synthetics and plated metals would constitute the jewelry industry, There would be little reason for anyone to go to the effort and expense of searching out the comparatively small number of natural gems avail- able for resale to the public, On the contrary, tradition has established the importance of the principal natural gems' and has associated them with genuine achievement in the church, business, family and other groups and associations, Achievement of any kind has in itself an element of rarity, and thus it is effectively symbolized by the rare. In view of this, man-made synthetics and imitations will never take the place of the natural stone, no matter how beautiful they are, other than for those who cannot pay the price of the natural, Even here they are only accepted as a substitute and, as such, are valued only at production plus handling costs.
PortabilityAnother factor contributing to the importance of gems is PORTABILITY. This applies to any fine gemstone because it represents a high concentration of value in a small object, permitting the owner to transport great wealth effectively on his person. This is what gives gemstones a universal security value I perhaps greater than any other known commodity, This is the factor that influences royalty and many wealthy families to invest a certain amount of their funds in jewels. When everything else fails, even their government, they can take or send their gems out of the country and realize a return on them quickly, This has always been a factor of great importance in Europe, General insecurity in recent times has given weight to the portability of gemstones as a factor in the consideration of their purchase.