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Mineral Specimens, Gems, Jewelry & Gifts



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CHEMISTRY: Further down in this page
CRYSTALLOGRAPHY: Isometric
REFRACTIVE INDEX:
Uvarovite, 1.74 - 1.87
Grossular, 1.72 - 1.80
Andradite,1.88 - 1.94
Pyrope, 1.73 - 1.76
Almandine, 1.75 - 1.83
Spessartite, 1.79 - 1.81.
HARDNESS:
Grossular and Uvarovite, 6.5 - 7.5
Andradite, 6.5 - 7
Pyrope, Almandine and Spessartite, 7 - 7.5
SPECIFIC GRAVITY:
Uvarovite, 3.4 - 3.8
Grossular, 3.4 - 3.7
Andradite, 3.7 - 4.1
Pyrope, 3.65- 3.87,
Almandine, 3.95 - 4.3
Spessartite, 3.8 - 4.25
CLEAVAGE: None

The Garnet Species are as follows.


Pyrope (magnesium aluminum silicone oxide)
Almandine (Iron aluminum silicone oxide)
Spessartite (manganese aluminum silicone oxide)
Uvarovite (calcium chromium silicone oxide)
Grossular (Calcium aluminum silicone oxide)
Andradite (calcium iron silicone oxide)

With the exception of blue garnet is found in every color of the spectrum. You may have heard
of other names than red, to describe different garnet types. Some of these names are. Tsavorite (Emerald Green) Rhodalite (pink-purple) Mandarin (bright orange) Thai (reddish orange)
Grape (almost purple)

A little lore:
Garnet has been dubbed the gem of faith, constancy and truth. Asiatic tribes carved garnets into bullets in the belief that their fiery color would inflict more deadly wounds. They were ground
into powder for the treatment of fever or jaundice. If the cure didn't work, the apothecary was accused of using an imitation.

Garnets are fairly hard and durable gemstones that are ideal for jewelry use. Garnets have long been carried by travelers to protect against accidents far from home.

The name garnet probably comes from pomegranate. Many ancient pieces of garnet jewelry are studded with tiny red stones that do look a lot like a cluster of pomegranate seeds.

Present Day Garnets:
Garnet has become increasingly favored in recent years. One of the most popular has been. Rhodolite: A lively violetish-red color liken to rose wine. Garnets of this color are also found here in Idaho. Our stones are as nice as any found elsewhere

Spessartite: encompasses the oranges from tangerine to rootbear. The one called Mandarin, a newly discovered garnet from Namibia. Is a very bright orange. It is the most popular of this variety.

In the late '60s a new garnet was discovered which made green an important garnet color. This
is the tsavorite, named after the Tsavo region of Africa. Its color may resemble emerald. The increasing scarcity of fine emerald has contributed to its importance.

The very rare demantoid variety of andradite is an emerald green with diamond-like fire. Uvarovite garnet may also be emerald green, but it is found only in tiny sizes. There is also a translucent green grossularite which resembles fine jade.

Grape Garnet, Mined in the Orissa district of Northwest India. Is a mixture of almandite & spessartite. It is an intense purple-red variety of garnet, that has a distinctively different in
color than ordinary rhodolilte or amandine garnet. These garnets can be purple and could be easily confused with amethyst.

Grape Garnet is a small fraction of Indian garnet production. For many years this material was badly faceted. The stones were dull purple set in silver jewelry or as beads. But careful selection of rough and precision faceting brings out its unique fire and color. The result is an intense
purple-red hue that flashes and sparkles even in low light, and is stunning in sunlight.

Color Change Garnet In this mixed garnet from Africa you can observe the distinctive color change as this gem switches from yellowish green under fluorescent light to a purplish red. It
may also be highlighted by flashes of burnt orange.

Less Common End Member Garnet Species:
Calderite: Mn3Fe3+2(SiO4)3
Goldmanite: Ca3V2(SiO4)3
Hydrogrossular: Ca3Al2(SiO4)3-x(OH)4x
Hibschite: Ca3Al2(SiO4)3-x(OH)4x (where x is between 0.2 and 1.5)
Katoite: Ca3Al2(SiO4)3-x(OH)4x (where x is greater than 1.5)
Kimzeyite: Ca3(Zr,Ti)2[(Si,Al,Fe3+)O4]3
Knorringite: Mg3Cr2(SiO4)3
Majorite: Mg3(Fe,Al,Si)2(SiO4)3, discovered in a meteorite!
Morimotoite: Ca3Ti4+Fe2+(SiO4)3
Schorlomite: Ca3(Ti4+,Fe3+)2[(Si,Ti)O4]3

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