Andalusite is named after Andalusia, the province of Spain where it was first discovered. Andalusite is a strongly pleiochroic gem that shows different colors when viewed from different directions. While it is a strikingly beautiful gem, it is largely unknown by the gem buying public. With a hardness of 7.5 on the Mohs scale, it is very suitable for all kinds of jewelry.
Andalusite colors Buying Andalusite Where is Andalusite found? Common Andalusite Treatments World-famous Andalusite Andalusite gemology Andalusite legends & lore
Andalusite colors Andalusite is pleochroic, which means different colors in different directions. When cutting pleochroic gemstones, such as iolite and tanzanite, the trick is to minimize the pleochroism and to maximize the single best color. Andalusite requests the opposite: cutters try to orient the gem to get a pleasing mix of colors, like orangey brown and a yellowish green or gold.
Buying Andalusite Color The colors of andalusite cover the range of yellow-green, green, brownish red and reddish brown. Due to the style of the cut each gemstone carries two colors that also differ in intensity, or blend into a mosaic.
Lighting The attraction of andalusite comes from its play of colors if one changes the direction from where to look at it. A similar effect is gained when the light comes from different directions.
Clarity Transparent andalusite of gemstone quality is rare. Dark inclusions produce cruciform shapes in a variety called chiastolite.
Cut The andalusite nature, which shows shades of brown, green and reddish brown depending on the orientation of the crystal, can be enhanced by specific orientation and cut. Those cuts with a long axis such as an oval, marquis or emerald cut tend to show one color near the center and a second, usually darker color near the ends. Square and round cuts usually blend the colors into a mosaic.
Andalusite location and deposits Deposits are found in Australia, Brazil, Canada, Russia, Spain (Andalusia), Sri Lanka and the United States.
Common Andalusite treatments There are no treatments to enhance the gem.
World-famous Andalusite As a lesser-known gemstone, andalusite hasn't gained fame as of yet.
Andalusite gemology Species: Andalusite Color: Yellow-green, green, brownish-red, reddish brown Chemical composition: AI2,SiO5, aluminum silicate Crystal system: (Orthorhombic), thick columnar Hardness: 7.5 (Mohs scale) Specific gravity: 3.05 - 3.20 Refractive index: 1.627 - 1.649 Birefringence: -0.007 to -0.013 Optical character: Color of streak: White Absorption spectrum: 553, 550, 547, 525, 518, 495, 455, 447, 436 Fluorescence: Weak; green, yellow green
The Andalusite zodiac, myth & legend As a lesser-known gemstone, andalusite produces a blank page in the books of myth, history, wisdom, the zodiac scheme or the relation between planets and mankind.
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