Andalusite

Many varieties of stones are alike, especially in the untrained observer. Given a collection of light blue stones - such as topaz, aquamarine, zircon, iolite , apatite and fluorite - even many in the gem trade would be hard to identify each variety, without the use of certain tools of gemology.

But there are stones that have a unique look that is difficult to confuse with other gems. Andalusite is a good example. Andalusite has such a distinctive combination of colors, and those marked pleochroism, as do abnormally colored tourmaline could never be mistaken for andalusite.

pleochroic gems seem to have different colors or color depth when viewed from different angles. The effect is caused by different absorption of light rays in doubly refracting crystals. Among the gems that are strongly pleochroic andalusite, iolite, kyanite, kunzite, sphene and unheated tanzanite. There are pleochroic gems dichoric - displaying two different colors; kunzite is an example. Others are said trichroic, as andalusite.

Andalusite displays shades of yellow, olive and reddish brown depending on the orientation of the crystal. The pleochroic effect can be enhanced by the specific orientation and a cup. These cuts an axis, like an oval, pear, marquis or emerald cut tend to show a color near the center and a second, usually darker in color near the ends. round and square cuts usually mix colors in a mosaic.

Andalusite is usually classified as one of the lesser known stones. Transparent material quality of stone is rare, so you're unlikely to find andalusite in your local jewelry store. It was mainly a collector stone, but some jewelry designers have begun to integrate into their conceptions.

Andalusite is named after the Spanish province of Andalusia, where he was discovered. andalusite deposits are also found in Australia, Brazil, Canada, Russia, Sri Lanka and the United States.