Factors determining the value of a gemstone:
Many factors set value. Things like weight, intensity of colour, size, rarity, and quality alongwith the country of origin are deciding factors for the price it commands. Gemstones may be accompanied by a lab report listing the colour, cut, clarity and weight. They may also contain a comment about treatments or origin. Certain gemstones such as ruby or sapphire can receive a premium in the market if they are believed to be from a particular country (origin). Nature produces far fewer of the top-quality gems, so there is good reason for the greater price.
The strength and purity of a Gemstone’s colour is of prime importance. The International Coloured Gems Association divides the Colour component of gemstones in 3 main categories: Hues (red, green, blue, etc.), Saturation (strong, pastel, red, pink, etc.), and Tone (dark or light). There is no established right or wrong colour, and there are literally thousands of shades of red, blue and green. Therefore, you should make your selection according to your own personal taste.
Picking a perfect gemstone is a very personal matter often depending on the personality and complexion of the person you're buying it for. Varying hues between absolute colours are sometimes preferred and are more affordable than the pure gemstone. For e.g. a bluish green sapphire is a lot more affordable than a pure deep blue one. The more pure and rich the colour is, the more expensive the gem is going to be. Although these slight colour variations are almost invisible to the naked eye, it doesn't compromise the quality of the stone you're buying. A strong bold colour would be best suited for a powerful personality but maybe not for someone shy. Pure gemstones are very valuable and require a lot of attention but in grading terms, the pure clear intense colours are the most preferred, and also the most expensive.
The cut of a Gemstone is of extraordinary importance. The proper cutting emphasizes the richness of the Gemstone’s inherent colour, which is a focal point of the gem’s beauty that attracts the eye.
Remember to not get confused between the shape and the Cut of a gemstone. The Cut looks into the how well the shape has been executed, e.g. the perfect round or pear shape stone, not the shape itself. A good Cut is what differentiates a good gemstone from a bad one, and doesn't always have to be more expensive. An ideal cut reflects the maximum light with almost no pockets of darkness anywhere on the stone. These are considered the best you can buy since they produce the maximum brilliance and are the most beautiful. There are no rules to cutting a perfect gemstone since the inclusions sometimes bring out the best in them. But care should be taken to observe the intensity of the Colour of the gem once cut, since some of them tend to lose their brilliance as they get smaller. However, we recommend you also check the Colour and Clarity of the stone while looking at its Cut to get the perfect gemstone.
While the clarity of a Gemstone is an important feature, it is equally important to remember that completely flawless Gemstones are very rate. Inclusions are inherent to practically every Gemstone and are nature’s way of adding variety and individuality to a Gemstone. Even the most expensive contain some inclusions.
Clarity in gemstones work very differently from Diamonds, and sometimes it's the little imperfections that make the stone come alive. While Clarity is a very important consideration in a gemstone, there is no standardized system to analyse the grades of Clarity for gemstones. Gems like the ruby, emerald or sapphire are rarely clean and pure, despite their intense colour, while the amethyst, aquamarine or the blue topaz are normally clean. But remember, sometimes it's the impurities or inclusions that enhance the stone and reflect the light, allowing it to sparkle so it's best to look at the intensity and hue of the Colour first before examining the Clarity of a gemstone.
Carat weight :
The size or weight of a Gemstone also affects its value. Carat is the standard weight of the gemstone, normally about 1/5th of a gram. Each carat is then divided into points, which is 1/100th of carat. Carats of a gemstone are the easiest to gauge and directly proportionate to its cost since larger stones are always rarer. But Carat does determine the size of a gemstone since the density of the stone plays a role as well. E.g. Opal has a light density while Zircon is heavy and often the same carat may no equal the same size, or the same value.
There are many aspects that determine the Cost of gemstones. The cost for mining and procuring gemstones fluctuates based on a demand and supply in the market. The larger, finer and rarer gems are often bought by the best of the dealers and are seldom available in large quantities. Also, if the mining for gemstones has to go deeper into the Earth's core, there are involuntary extra overheads like more machinery, more fuel, more manpower, which add to its value. The deeper they need to dig, the more expensive the gem will be, and sometimes when the productions costs are too high, the mining stops. However, gemstones are fashionable and seasonal depending of a current industry trend or some unforeseen celebrity endorsement, so their prices tend to fluctuate like any other commodity in the market.