Almandine Garnet
ISOMETRIC

Almandine

Fe3Al2Si3O12

Hardness
7.5–8.5
Refractive Index
1.780–1.810
Spec. Gravity
4.3
System
Isometric
View Mineral
Almandine is the most common form of the gemstone Garnet. The term Garnet describes a group name for several closely related minerals that form important gemstones, and Almandine is an individual member mineral of the Garnet group. Almandine is usually opaque and unfit for gemstones use; though the less common transparent to translucent forms make fine gemstones. In the gem trade, the term Almandine is rarely used on its own. It is either generically called "Garnet", or "Almandine Garnet".

About

Almandine is almost invariably dark in color, and it forms dark red to reddish-brown Garnet gemstones. Almandine is the hardest form of Garnet, and a pure deep red is its most valuable color. Almandine Garnets are occasionally hollowed in their underside to allow more light to enter a stone, giving a cut gemstone a lighter appearance. If the bottom of an Almandine gemstone is covered by a jewelry setting, the only way to easily determine if  it is hollow is by its lighter weight.

Uses

Almandine is cut into dark red Garnet gemstones and used in all forms of jewelery, especially rings, earrings, and pendants. Lesser quality Almandine is polished into cabochons and beads for use in bracelets and necklaces. Almandine is also tumbled into smooth irregular stones for jewelry. Very dark or heavily included Almandine garnets are cut and polished into cabochons, and asterism (in the form of a weak four rayed "star") is observable in Almandine garnets from certain localities.

Varieties

common  ·  uncommon

Treatments & Enhancements

Garnet gemstones are not enhanced, and their colors are always natural.

Sources

Although Almandine is common worldwide, gem forms of Almandine are much less prevalent. Sources include India, Sri Lanka, China, Madagascar, Australia, Brazil, and the U.S. (Alaska, Idaho, North Carolina, and New York).

Similar Gemstones

Most dark red gemstones on the market are either Almandine or Pyrope Garnets. Almandine and Pyrope Garnets can be very difficult to distinguish from each other, though Almandine is usually the darker of the two and is heaver. Dark red Spinel and Rubellite Tourmaline can also resemble Almandine, and Ruby is usually a lighter red color.

Further Reading