Since the earliest times, gemstones have been a highly valued commodity, both for their inherent beauty and their other characteristics. Royals have long appreciated gemstones and worn them as jewelry and adornments on their crowns and other regal garments. In more recent years, gemstones’ monetary value has come into play as well. While prices fluctuate, as do supply and demand, since the end of the 1980s, the value of gemstones has been steadily rising. The diamond market, too, has increased significantly, which is good news for those with investments in the industry.

Price and value are dependent on many factors, including stores of the stones, mining, popularity, demand, and other variables. While it may be difficult for an untrained buyer or collector to judge a particular stone’s worth, with understanding of the given gemstone and current market prices, it is possible to learn how to value gemstones.

While diamonds are particularly valuable, the colored gemstone market, which is divided into precious and semi-precious gems, has been steadily rising in the last few years as well. This has affected prices in both categories of gems: the precious, and semi-precious.

Precious Gemstones

The three types of precious gemstones are emerald, ruby, and sapphire, with the latter two composed of the same material – corundum. Corundum that is red in color is known as a ruby. All other color variations of corundum are known as sapphires. Sapphires appear in many hues of blue, pink, purple, yellow, brown, and green as well as other variant shades. Emeralds, the third precious gem, are green.

Semi-precious gemstones run the gamut of color, chemical composition, and place of origin. Amethyst, citrine, opal, quartz, topaz and aquamarine are all types of semi-precious stones, and there are many others. The list of all semi-precious stones is vast, and they can add a special bolt of color to gemstone jewelry.

However, despite the variety of semi-precious stones, there has always been great interest in the three precious jewels, ruby, sapphire, and emerald. While rubies and sapphires are made of corundum, emeralds come from the mineral beryl. The amount of chromium inside the rough stone determines the intensity of the emerald’s green, which ranges from light to very dark and intense.

In addition to color, gemstones’ ‘hardness’ can be measured on the mohs scale, with rankings of 1 to 10. Diamond is the hardest material and is rated as 10 on the mohs scale. Corundum (as ruby & sapphire) is rated with a hardness of 9 points, and emerald is rated at 7.5-8 points.

While diamonds are used for their durability and strength as well as their beauty, most people treasure rubies and sapphires for their beauty and investment value rather than for utilitarian purposes.

Purity, color and overall quality influence price in precious stones and diamonds. Although there is no official valuation reporting group for corundum like the Rapaport List for diamonds, valuation is made through the assessment of a stone’s color, purity, size, and qualities like its cut and the degree of inclusions within it. Inclusions inside gemstones are small imperfections like cracks or spots, and they are very common. It is often these inclusions that determine the quality of a stone. In diamonds, for example, inclusions will generally consist of small white or black spots in stones rated VS- I.

When beautiful stones contain small inclusions or possess an unsaturated color, it may be decided to put the stones through a process of heating. Heating a gemstone is exactly what the name describes. Many people don’t understand this procedure and wonder if a precious stone that has been heated can still be considered natural. A heated gemstone is absolutely still natural and is not deemed ‘treated’. Heating simply takes a rough stone that has been mined from the ground, puts it into an oven, and literally cooks it. This process usually helps to improve the color saturation of the stone, and if there are light inclusions, heating may remove them.

However, heating will not improve any cracks in a stone: if cracks exist, heating does not remove them, and in fact, may damage the stone. It is important to note that at this stage, heating is customarily performed only on rubies and sapphires. While it is believed that heating can improve the appearance of particular stone, it isn’t a guarantee that a plain stone, once heated, will blossom into a beautiful gem. And regardless of the result of the process, heating will cause the jewel to be devalued.

Un-heated gemstones are unique, untouched (besides cutting & polishing) products of our planet, and therefore they command a much higher price than heated stones.

Emeralds are not treated by heat; they are, however, treated with oil, which again, is as simple as it sounds. Manufacturers put the stones in a variety of oils, for different periods of time, with different temperatures, and this can make the stone appear much more pleasing to the eye. These processes, heating and oiling, are, of course, detectable, and laboratories issuing gemstone certification will state the degree of treatment an individual gem has received.

Another important determinant in the value of a particular stone is the origin of the gemstone. Jewels of specific origins possess certain characteristics and traits, and this is one factor that influences a gemstone’s price. There are gemstone mines throughout the world. Rubies are commonly found in parts of Asia and Africa. Today, the Mozambique Ruby is produced in high numbers and it is considered a high-quality stone. The Burma Ruby has always been extremely popular, and today, the price of a good quality Burma Ruby can be huge in comparison to rubies mined elsewhere.

Sapphires are mined in many places around the globe. Today, most sapphires come from mines in Sri Lanka and Burma. A Burma Sapphire is more expensive than a Sri Lankan Sapphire, but by no means will it be as high priced as a ruby; rubies are far rarer than sapphires. However, a good-quality sapphire originating from Kashmir (north India) can demand an exorbitant price. However, like all gemstone prices, these prices reflect the stone’s origin, color that the origin produces, and quality of the particular gem.

Emeralds are commonly found in parts of South America and Africa. Today, the most popular origin is Columbia, as the country produces an electric green color that is combined with great luster. Brazil is also a popular mining site, and outside of South America, Zambia produces emeralds that are highly appreciated for their grassy green color.

With mining companies constantly looking for new areas of mineral-rich lands and gem investments in certain stones like diamonds and precious and semi-precious gems are gaining in popularity.  The gemstone market, which is benefiting from the increase in popularity and prices, is expected to continue to develop into an important investment market. After all, gemstones are timeless creations that our planet produces; gems offer significant appeal and are poised not only to compete with the diamond market but to emerge from its shadow and, once again, dominate the global market.