ALMANDITE GARNET MINERAL FACTS Nevada Turquoise gem stones
The Gem and Mineral Collector's Photo Gallery by Nevada Outback


Almandite Mineral Facts:

Chemical Formula: Fe3Al2(SiO4)3
Iron-aluminium garnet. Ferric iron replaces aluminium
and magnesium replaces ferrous iron.

Colors: Deep red, brownish red or black.

Hardness: 7

Density: about 4.1 to 4.3

Cleavage: None

Crystallography: Isometric, hexoctahedral
Usually distinctly crystallized; also in rounded grains; massive granular, coarse or fine. When crystalized, commonly forms dodecahedron and trapezohedron, often in combination. Hexoctahedron observed at times.

Luster:.Vitreous glassy luster. It is transparent or translucent.

Optics: (Refractive Index):  1.8100

Black Almandite Garnet

Black Almandite Garnet

Composition, Structure and Associated Minerals:
Almandite is a common garnet is an extremely frequent mineral in metamorphic rocks, mica schists, and gneiss; also in granites, andesites and in some ore veins. The name is derived from the city of Alabanda, now known as Doğanyurt in the Aydin Province, in the Asian part of Turkey, where in ancient times garnets were cut and polished. It is one of the commonest of all garnets.  Almandite furnishes nearly all the garnet material which is manufactured into commercial abrasives. Transparent varieties are also used as gems. It is widely distributed in schists and gneisses. The chief sources are the gem gravels of Sri Lanka and the Minas Novas district of Brazil; and the mica-schists
of various parts of India, notably those of the Sarwar district of Kishangarh State, and those of Rajmahal in Jaipur State.

Identification and Diagnostics
It is fusible before the blowpipe to a black magnetic mass.
Garnets, when in crystals, are easily distinguished from other similarly crystallizing substances by their characteristic isometric crystals, color and hardness, etc. Massive garnet may resemble vesuvianite, sphene, zircon or tourmaline. It is distinguished from zircon by its easier fusibility and from vesuvianite by its more difficult fusibility; from tourmaline by its higher specific gravity, and from sphene by the reaction from titanium. It frequently requires a chemical analysis to positively distinguish between the different members of the group, or the percentages of each element in an individual specimen

Occurrence, Localities and Origins:
Its Its best known occurrences in North America are at Yonkers and at various points in the Adirondacks, N. Y., at Avondale, Pa., and on the
Stikine River, in Alaska. The varieties of almandite that are transparent are used as gems. Other varieties too dark or included for gem use are crushed and employed as abrasives. Abrasive garnet has been produced in the mountain regions of New York, New Hampshire and North Carolina. The rock is crushed and the garnet separated by hand picking, screening, or by jigging. The crushed material is used largely in the manufacture of garnet paper. Almandite, of gem quality, is found in northern India, Brazil, Australia, Tanzania and in several localities in the Alps. Most Almandite gems are very dark in color, so that larger stone appear almost black and reflect little light. Fine crystals, although for the most part too opaque for cutting, are found in a mica schist on
Garnet Creek close to the Stikine River, Alaska. Garnet is Schist is known from several locations in Alaska.

Return to the Mineral Collectors Information Page

Almandite Garnet, Alaska

Almandite garnet, Stikine River, Alaska



Please note that the author, Chris Ralph, retains all copyrights to this entire document and it may not be reproduced, quoted or copied without permission.

Turq_nev_6b.gif (5020 bytes)


Nevada Outback Gems

Find out more by checking out All of our links below:

View our Contemporary Turquoise Jewelry - Wearable Artwork! View our Unique Gem Quality Turquoise Cabochons
Premium Jewelry, with Gemstones of all types Top Quality Loose Gemstones - Gemstones of all types
Rare Crystals and Gemstone Rough, all types Our Free Colored Gemstone Information Encyclopedia
Chris' Gold Prospecting Encyclopedia Take a virtual tour of our Nevada Turquoise mines
Miners Reference Pages         California Gold Rush Stories More Info about Turquoise, the Beautiful Gem
Metal Detecting with the MXT Metal Detector Nevada Outback Gems Homepage
Build Your Own Mining Equipment Investing in Gold and Precious Metals
Basic Placer Mining More information about us - Nevada Outback Gems
Locations to Prospect for Gold The Rockhound's Corner Nevada Outback Library and Bookstore - Learn more!
Chris's Prospecting Adventures About Nevada Turquoise More Info about Gem Cutting Tanzanite Jewelry
Nevada Outback Gems Site Map Make Your Own Jewelry Buy Safely on EBay: avoid fraud and scam artists