Multicoloured Stones Stones which consist of various colours, such as bloodstone (green and red), tourmaline (many combinations) and the opal (all colours) are, obviously, more complex in their magickal make-up than single hued stones. For most of these, simply look at the colours individually and determine the stone's uses by combining the energies of each. Opals are a special case, as are all stones which exhibit rainbows or a variety of colours. [Encyclopedia of Crystal, Gem, and Metal Magic-Scott Cunningham]