Tourmaline is called turmali in hindi. Having one of the widest colour range in gemstone category, it has great healing properties. Every colour of tourmaline has their own specialty. A single piece of tourmaline with multiple colours is called watermelon tourmaline.
Having a complex chemical composition structure, it could not be made in synthetic form & thus they are always natural.
Many different colours of tourmaline are used as great substitute for different gemstones.
For ex 
Red tourmaline( rubellite) for ruby
Green tourmaline for emerald
Blue tourmaline for blue sapphire .