Color :
White diamonds color range from D (colorless, the purest white) to Z (light color).
D, E and F are colorless diamonds, G, H , I and J are near colorless , K and L are faint color, M to Z have a light color.
Tanzanite :
Tanzanite is a blue/purple silicate discovered in the 60s in Tanzania. Naturally-formed tanzanite is extremely rare.