Colour is the most important characteristics among the gemstones that make them look beautiful for various purposes. Initially the compound is colourless or mostly in grey or black colours while extracting. The variation in colours for Tourmaline depends on the various composition and chemical structures with various mineral compounds. There are around 32 different colour variations for Tourmaline gemstone crystal. The, colourless tourmaline is rarest and also least valuable crystal as well. The most common found Tourmaline crystal is black and this is more valuable, too (Ertl, 1997). Generally, it is found that there are 2 or more than 2 colours available in single gemstone of tourmaline. The tourmaline crystal gemstone exhibits strong pleochroism that means this crystal can demonstrate various colours based on the angle these crystal gemstones are viewed or observed.
Pink, red, brown to yellow colours of such crystal gemstone is coloured with presence of manganese constituents while on the other side Iron and titanium derives the colours from greenish to bluish-black (Schumann, 2006). The most important factor for quality of this crystal gemstone is the colour intensity and saturation. Tourmaline is six-member ring cyclosilicate. This has trigonal crystal system and it occurs in form of long, prismatic, slender and columnar crystals. This is often found as triangular as cross section with sometime curved striated faces. Sometime, the shape is asymmetrical in nature. The most common way of identifying Tourmaline is to find in form of three-sided prism. There is no other material which has 3 sided prisms around.