StarGemstones.com | Star Garnet | Magical Gems that display Asterism

What are Star Garnets?

Star garnets, also known as Asteriated Almandine, are a special form of the gemstone garnet. While colored like other garnets they display a reflection-like image of a four or six pointed star caused by the inclusion of rutile needles (an effect known as Asterism). These 12-sided (dodecahedron) crystals range in size from sand particles to golf-ball or larger size. Sometimes a star garnet may additional stars when rolled around and viewed from a different angle. Each arm of the star might show another star when turned at the proper angle. Not all stones display this effect and hence these gems fetch extra value. There are very few cabochon gem cutters that are able to correctly orient a star garnet, and even fewer are able to maximize the size and quality attainable from the rough gem. Most star garnets look blackish red or dark purplish red. Bright red star garnets are said to cost more than good star rubies! Star garnets are known by the name of Sterngranat in German.

A four-ray star garnet

Sources of Star Garnet

The star form of garnet is relatively rare, occurring in quantity only in a few places such as India (red), Russia (brownish purple), Brazil (purple), and the U.S.A. (purplish brown, usually quite fractured internally). However, today most star garnets come from Idaho (in the U.S.A.) and India. Idaho is said to be the only place which produces six-ray star garnets. Most of the Star Garnets are nearly opaque and dark purplish red in colour. Large sizes and really good quality stones are very hard to come by.

Idaho (Emerald Creek) Star Garnets

Majority of star garnets from Idaho are very dark, almost black, until they are viewed in direct sunlight or strong bulb light where you can see their deep purple colour. Very few are dark red and show red in the sun, but the star is generally weak. Fine 6-ray star on a star garnet that shows red or pink in the sunlight are rare. The unique color of Emerald Creek garnets comes from mineral impurities such as manganese, magnesium and iron. Most of the star garnets found in Idaho display four-ray stars and greatly outnumber six-ray star garnets.

Garnet Myths, Legends & Beliefs

Garnet has been officially adopted as the birthstone for January by the American National Association of Jewelers in 1912. It is also the gemstone for the 2^nd and the 6^th Wedding Anniversary.

Garnet's powers include healing, strength, and protection and it is often worn to relieve inflammations of the skin. It is also believed to regulate the heart and blood flow and aid in curing depression. In earlier times, garnets were exchanged as gifts between friends to demonstrate their affection for each other and to ensure that they meet again.

General Characteristics of Garnets:

Colour	Virtually all colours (Star Garnets are mostly found in hues of red)
Mohs Scale Hardness	6.0 to 7.5 (Star Garnets have hardness of 7.5)
Refractive Index	1.72 – 1.94
Crystal habit	Rhombic dodecahedra or cubic
Crystal system	Isometric
Luster	vitreous to resinous
Optical Properties	Single refractive, often anomalous double refractive
Birefringence	None
Streak	White
Specific gravity	3.1 - 4.3
Major Varieties	Pyrope Garnet, Almandine Garnet (includes the famous Demantoid Garnet), Spessartite Garnet, Andradite Garnet, Grossular Garnet (includes Tsavorite Garnet), Uvarovite Garnet

Some Pictures:


A star garnet displaying several asterisms	A Star Garnet from Idaho

Next: Learn about Star Diopside | Buy Star Garnets