Gemstone Colour

The beautiful colour of a gemstone is its most defining characteristic and also determines its value. Colour of a gemstone is evaluated and described in these three ways:

• 

  HUE

  The dominant colour that you see.
  Also known as the primary colour.
   

• 

  SATURATION

  The intensity of the
  colour.
   

• 

  Tone

  How light or dark
  the colour appears.
   

People assume that the darker the stone the better the quality. Unfortunately it is not true, a truly dark stone is dull and lifeless. The best stones are rich and vivid with a medium tone. And since no two people perceive and appreciate colour in the exact same way, desirable colour in gemstones owes a lot to personal preference.

Gemstone Clarity

Clarity is also a factor in determining quality and the value of a gemstone. In precious gems, a high clarity grade means transparency of the gemstone, allowing the full beauty of gemstone colour to be realized without interruption or interference by natural inclusions.

Generally most gemstones contain inclusions and blemishes but if they do not affect the durability of coloured gems then these inclusions or spots will not devalue much for the gems except diamond. Many gemstones that have characteristically low clarity, such as emeralds, can be highly valuable. And semi-precious gemstones are frequently valued for their interesting and unusual inclusions. Some varieties of coloured gemstones, such as aquamarine, blue topaz, and citrine, have naturally fewer inclusions while other gemstones, such as emerald and ruby, tend to have a higher rate of acceptable inclusions. A flawless gemstone is rare and usually expensively priced.

In general, gemstones clarity is described as below.

Gemstone Cut

Cutting a stone can really affect its quality in terms of its colour and clarity. A good cut showcases the gemstone's colour, diminishes its inclusions, and exhibits good overall symmetry and proportion.

Coloured gemstones are generally cut to maximize the beauty of their colour. To recognize quality in the cut of a gemstone, there are several points to consider. While cutting, colour of a gemstone is taken into account for optical efficiency. If a stone's colour is highly saturated, a shallow cut will allow it to pass more light, while a deeper cut may increase the vividness of a less saturated gem.

The different cuts and shapes of a gemstone found in general are shown below.

Gemstone Carat

Gemstone weight is expressed in carats. One carat is the equivalent to 200 milligrams. Gemstone sizes are frequently communicated in millimetres too. Since gemstones do not all have the same specific gravity, two gems that appear to be the same size may actually have very different weights like the example shown below.

Larger gemstones occur much less frequently in nature than smaller ones. Due to the rarity of large gemstones, the higher the carat weight, the higher the price per carat will be.