Multicoloured tourmalines
By Rajesh Kumar, Section Multicored Tourmaline
Posted on Sat Mar 31, 2007 at 02:21:10 AM EST
Tourmalines are true miracles of colour. Crystals with only one colour are fairly rare, there mostly being various different colours and colour nuances in one and the same stone. The spectrum is so varied that the tourmaline family alone would suffice to cater to the gemstone wishes of every woman and every man in a particular colour or colour combination.
Often, Nature conjures up tourmaline crystals from which gemstones with a particularly subtle multi-colouredness can be cut. You may well ask how that is possible. Tourmalines are mixed crystals of aluminium boron silicate with a complex and changing composition. It's a rather complex mineral group. Even minor changes in composition cause completely different colours. And that is how, on one and the same crystal, although it has grown quite naturally, completely different colours can occur, mostly in elongated columns one above the other, as if Nature had piled coloured rings one on top of the other. The crystals themselves can be as slim as a knitting-needle or as thick as a man's thigh. Some display coloration in which the shades vary only slightly, whilst others have starkly contrasting colours or zones of colour. Since tourmaline crystals have often grown in close proximity to one another, their cross-sections can also contain triangles which are closely joined together and gathered around a nucleus.
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