GARNET
Garnet
is the accepted birthstone for the month of January. It is also the accepted
anniversary gemstone
for the second year of marriage. Garnet is not a
single mineral but rather a group of similar minerals known as the "Garnet
group." The most common deep red Garnets are Almandine/Pyrope, which is
what most people mean when they say "Garnet." Pyrope Garnet is found
many places in the United States, particularly in Arizona where the pebbles are
excavated by ants while digging their holes. The ants then deposit the gems in
their refuse mounds, giving this stone the name "ant-hill" Garnet!
Garnets are able to withstand enormous heat, up to 1400 degrees Fahrenheit. It
derives its name from the Latin granutus , meaning "like a grain"
(i.e., a pomegranate seed). Legend holds that Noah hung a large garnet in
the ark for illumination. In 1905 a Garnet necklace
dating from 3500 BC was found in Egypt around the neck of a young male's
mummified body. It reportedly also gives its
wearer guidance in the night, protection from nightmares, and according to the
Egyptians, is
an antidote for snake bites and food poisoning. It was also thought to have a
special affinity with
the blood.
Garnet is a hard, durable, often
very brilliant stone, available in many
colors. You may be surprised to learn that garnets are found in every color
except blue,
including brilliant green tsavorite garnet, raspberry pink rhodolite garnet,
and orange Malaya
garnet. The Tsars
of Russia favored rare
green demantoid garnets, which are more highly dispersive than diamond. Tsavorite
is a member of the garnet family and is often mistaken for other (usually more expensive) gems. It is one of the most
beautiful, and all but a few would assume it was an emerald of the finest quality. In fact, it
is "clearer", more brilliant, and more durable. There is also a rarer green garnet, called
demantoid, which costs slightly more than tsavorite but which, although slightly softer, has more
fire. These gems offer fine alternatives to the person desiring a lovely green gem who can't
afford emerald. While still rare, expensive gems themselves,
they are far less expensive than an emerald of comparable quality. Rhodolite Garnet is distinguished from others
of the Garnet family by its pink-violet to purple-red color. One of the lesser
known Garnets, it as actually a Pyrope-Almandine mix giving it a pleasing
rhododendron-like color. The original locality for Rhodolite was Cowee Creek,
North Carolina. Stones found there are small (1-2 carats), but new finds in
Africa have yielded gems over 25 carats!
Depending
upon the variety, quality, and size, lovely garnets are available for under $20
per carat or
more than $3,000 per carat. Garnet also occurs in certain shades of red that
have been mistaken
for some varieties of ruby. And in yellow it has been confused with precious
topaz. Even blue color may occasionally be seen in a very rare color change
phenomenon, which some garnets exhibit. It is best known in a deep red variety, sometimes with a brownish cast,
but it is commonly found in orangish brown shades, and brilliant wine red shades as well. Garnets
offer enough variety in appearance to suit every taste, as well as an
outstanding price
range to suit every pocketbook.
As with all gemstones, care should be taken to protect
it from scratches, sharp blows, and extreme temperature
changes.
TREATMENT: There is no known treatment for
Garnets
MOHS HARDNESS: 7-7.5 (although hard, Garnets abrade easily and should be
treated with care) Andradite (Demantoid) 6.5-7
CHEMICAL COMPOSITION: Almandine: Mg 3 Fe 2 Si 3 O 12
Pyrope: Mg 3 Al 2 Si 3 O 12
REFRACTIVE INDEX: n= (approx.)1.75-1.766
(The angle light is bent traveling through a gemstone) Spessartite 1.81,
Andradite 1.888
DENSITY (SPECIFIC DENSITY): 3.87-3.95
(The number of times heavier a gemstone is compared to water)
PRINCIPAL SOURCES: Mozambique, Thailand, India, Sri Lanka, Arizona, Brazil
Rhodolite Garnet
TREATMENT: There is no known treatment for Rhodolite Garnets
MOHS HARDNESS: 7-7.5 (durable and well suited for all types of jewelry)
CHEMICAL COMPOSITION: Mg 3 AL 2 Fe 2 Si 3 O 12
REFRACTIVE INDEX: 1.76
(The angle light is bent traveling through a gemstone)
DENSITY (SPECIFIC GRAVITY): 3.84
(The number of times heavier a gemstone is compared to water)
PRINCIPAL SOURCES: North Carolina, Tanzania, Rhodesia, Madagascar