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The Gemstones

 

Andalusite

 
 
 
 
 
Consumer Information

What color is it?: As shown by the photograph above, andalusite is a combination of two to three colors, depending on how you look at it. The two basic colors are green and brown as shown above. But later down this page I will show you something very unusual about this stone.

What is the story behind this gemstone?: This gemstone is a bit like tanzanite in that it shows two very distinct colors at the same time. The difference is that andalusite shows brown and green, rather than blue and purple of tanzanite. But the ability for any gemstone to split a single beam of light into these two very different colors that your eye can actually see is very, very rare in the gemstone world.

Can I wear it everyday?: Yes, andalusite is a very durable gemstone for wear.

Is it expensive?:  It can be. A fine quality andalusite can be a bit difficult to find and a bit pricey when you do. But it is well worth the effort and the price. Nothing else like it in the gemstone world. And you will certainly have something no one else on the block owns.

Is it a birthstone?: No

What do I need to know before going shopping?: Just be sure to call ahead. This is not a gemstone that many jewelers will carry. But the stones are available so don't hesitate to ask. But....look at the following photographs...

General Information

FGA students please look carefully at the above photographs. This is a different view of the same andalusite shown at the top of this page...only looking through a London dichroscope. Notice the change. From this direction the stone appears a rather intense brownish red, but when the polaroid filter is moved the gemstone turns colorless. This is the very same stone in the very same position...I promise. Too many gemologists expect andalusite to have brown/green trichroic colors. This is not always the case when you look at different directions. A stone just like this one cost me almost an hour on my practical exam for my FGA diploma because I did not consider that andalusite could be colorless and reddish brown. Look at the gemstone in the top of this page. Then compare then two stones shown above. And remember.....they are all three the same stone. Words to the wise from one who has been there...done that. Robert James FGA, GG

Source: Brazil, Sri Lanka, Canada, Russia, USA

Chemical: Al2SiO5 aluminum silicate

Formation: In pegmatite dikes and granite rocks

Crystal System: Orthorhombic

Unusual Properties: Extreme pleochroism unlike any other gemstone


For the gemological information on this gemstone we invite you to join us in the

International School of Gemology.