Sapphire color is the indicator of its value. A very dark Sapphire may be sold at HK $ 100 a card, but a nice cornflower blue Sapphire tens of thousands of Hong Kong dollar sale of each card. In the United States and Europe, people prefer the darker color of the Sapphire. In Hong Kong, consumers love the blue of the mid-depth, color Sapphire sold at higher prices. Sapphire on the arm away, and carefully observe its color is blue or black. If it is blue, then your choice though not far wrong.
Natural daylight and under artificial light stones. Stones in bright light seems to be light-colored, but in normal sunlight will be more "black".
To see if the color is uniform, the cracks will affect the appearance and durability of the gem. Such as the plume pattern stretch of the stone surface, the sudden impact (such as mahjong) will make the gem rupture.
Do not forget to observe the gem cutting and proportion.
5 sapphires and rubies, careful imitation and a few imitations of the real thing.