Colored Gemstones

Nature produces a variety of magnificent colored gemstones. The most popular seen in fine jewelry are ruby, emerald and sapphire.

Color is the primary characteristic used to determine the quality of a colored gemstone. Although clarity and brilliance too contribute to the stone's beauty and worth.

Gemologists grade a gemstone based on three components: hue, tone and intensity. Modern textbooks and many jewelers now substitute the word saturation for intensity. Today, many gemstones are enhanced, or treated, to improve their color to the naked eye. Some of these treatments are permanent and barely discernible, while others are noticeable and may cause the color of the gem to change over time. The customer should be educated on such enhancements so that he or she can make an informed buying decision.

For example, take the September birthstone, sapphire. In its blue variety (sapphire forms in nature in all colors except red), sapphire varies from pale watery gray-blue to deep greenish-blackish-blue, and each shade in between. Sapphire can be extremely common and low priced, or rare and expensive. This is the case with certain pure "electric" blue colors of sapphire or the very soft and extremely rare deep cornflower blue Kashmir stones. 
Diamonds Direct Birmingham procures sapphires from many sources in a variety of ranges of price, rarity and beauty.