Allanite
Brazil
3.47 carats
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Allanite is a member of the Epidote group. It is opaque, with a dark brown (sometimes virtually black) colour.
Allanite contains the rare earth elements Yttrium and Lanthanum.
Allanite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
|
| Physical Properties of Allanite | |
|---|---|
| Specific Gravity | 3.40 to 4.20, Tables of Gemstone Identification (2007) |
| Optical Properties of Allanite | |
| Refractive Index | 1.64 to 1.828, Tables of Gemstone Identification (2007) |
| Birefringence | 0.013 to 0.036, Tables of Gemstone Identification (2007) |
| Colour | |
| Colour (General) | Brownhttp://minerals.caltech.edu (2012) |
| Causes of Colour | Colored by iron and radiation damage and possibly by rare earth elementshttp://minerals.caltech.edu (2012) |
| Further Information | |
| Mineral information: | Allanite information at mindat.org |