Sapphire has been one of the most precious and sought after gemstones since ancient times. It has all of the attributes of a great gemstone. Its hardness is surpassed only by diamond. It comes in an enormous variety of vivid colours (not only the traditional blue) and has excellent brilliance. It is also tremendously rare in good qualities and large sizes. The most popular colours are blue, pink, orange and yellow, though there are many other beautiful colours available (such as purple, teal and green) for the person looking for something unusual.
The most valuable colour is bright blue. If a blue sapphire is too dark or too light it loses a great deal of value. Second in value are pink and pinkish orange sapphires. Sapphires from East Africa often show what is called colour-change. This means they appear to change colour quite dramatically when the stone is viewed in different light sources. For example, a colour-change sapphire might be purple under incandescent light and blue or teal in daylight. This makes for a unique stone that is in great demand.
Sapphires are rarely free from inclusions and flaws. A small number are acceptable, as long as they do not detract from the beauty of the stone. Most sapphires are heat treated. Untreated stones carry a small premium.
Sapphire is the traditional birthstone for September.