Cochise College
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gems
Roger
Weller, geology instructor
AMETHYST
Interesting Facts about a Pretty Purple Gemstone
By Jesika Cline Spring 2007
What is
it?
Amethyst is a variety of quartz known for its beautiful
purple color. In fact, when translated from other languages such as the Dutch
word “amethist,” the meaning is “violet”. Throughout
history many people across cultures and generations have been in awe of its
beauty. Amethyst is a very 
common gemstone and can be found in or on a wide
variety of rocks, including granite rock formations and agate geodes. It is
used to make jewelry in the form of cut stones, beads and calves, and is also
admired in natural form, ranging in size from very tiny singular crystals to
over 6 ft tall geodes.
Its
chemical make-up is SiO2 (Silicon Dioxide). With such a simple composition the
cause for its coloration has been debated greatly by scientists. Recently its purple color has been attributed
to the presence of manganese in quartz and the intensity of the color has been
determined to be affected by the amount of iron present. An interesting
property of amethyst which also affects its coloration is
its response to heat. If heated to temperatures as low as 250 degrees
Fahrenheit the crystals will turn to a yellowish brown colored citrine. This
phenomenon is why often Citrine is referred to as “burnt amethyst.”
http://www.wegnercrystalmines.com/22/imagesmf/MAR%202006/GIANT%20AMETHYST%20&%20PAT.jpg
Rock Stats
Chemical Makeup:
Color:
Various shades of purple; sometimes bluish, reddish or brownish
Index of refraction: 1.5-1.6
Birefringence: 0.01
Mohr’s Scale Hardness: 7
Cleavage: none
Pleochroic:
no
Specific Gravity 6.5
Si02 molecule formation
http://www.3dchem.com/molecules.asp?ID=184#
Where is it Found?
Amethyst
can be found all over the world, but varies in size, color and clarity based on
it surroundings. Below is a list of places where it can be found and which
types of crystals can be found in each location. A * symbol indicates a
location with exceptional specimens.
-
-
-Maine- Dark colored druzy. (Druzy means tiny quartz
crystals found on the surface of or within another stone)
-North Carolina- Blue tinged druzy
*-South
-Pennsylvania- Brown tinged druzy
-Vera Cruz- Pale average
crystals
*-Guerrero- Dark average
crystals
*-Mina Gerais, Rio Grande de Sul & Bahaia- Light to medium
colored ranging in size, some quite large crystals
*-Marba-
Pale to medium color large crystals
http://www.jewelinfo4u.com/images/amethyst_mines_map.gif
-
Italy- Pale varying in size crystals
Germany- Light druzy
*-Ural Mountains- Dark clear
large crystals http://www.umanitoba.ca/geoscience/faculty/arc/PICTURES/AMETHYST.JPG
What is it Worth?
Although amethyst is a very desirable hardness for a
gemstone, ranking closely to garnet 6.5-7.5, tourmaline at 7-7.5 and topaz at 8,
its abundance is what limits its ability to become tremendously expensive. It
is so readily available in stores around the world that even rather nice
specimens are relatively cheap in comparison to their other gem counterparts.
An example of this is easily demonstrated.
This 3.69carats garnet (pictured on the left), advertised
on http://www.mineralminers.com is
priced at $221.40 where as this 11.56 carats amethyst (pictured on the right), from
the same website is only $127.16. Both stones are fantastic specimens, but
because garnets are not as easily accessible, they are able to be sold for a
much higher price. Overall, the amethyst’s monetary value is direct reflection
of supply and demand.
If
looking for a simple necklace and earrings set of a medium quality color and clarity,
there are sets available for as inexpensive as twenty bucks. However
exceedingly nice specimens in the form of large cut stones and enormous geodes
can be upwards of several thousand dollars. Size, color, and clarity are what
determine the quality of a piece of amethyst, with darker, clearer, larger
specimens being of the highest value.
http://petrifinds.us/store/images/BrazilianGeodes_AmethystCathedral.jpg
Magical Powers and Other Fun Facts
One of amethyst’s most interesting claims to fame is
its supposed ability to prevent drunkenness. The word amethyst comes from the
Greek word amethystos
meaning “not drunk.” People were so
confident of the stone’s ability to battle alcoholism that frequently cups or
chalices were fashioned out of the stone to drink wine from in order to take
the ill affects out of the beverage.
More interesting mystical abilities include protection from
seduction (possibly related to its defense against alcohol), protection for
crops against locusts, quelling excessive stomach acid, and bringing good
fortune in war and for the ill. Yet more abilities include sharpening the wit,
turning away evil thoughts, making the barren woman able to bear children and
giving knowledge of the future in dreams.
Amethyst
is also known for being a symbol of God adorned on religious garments worn by
Jewish religious leaders and in the Roman Catholic religion ranking members traditionally
wear rings set with a large amethyst as part of their office. It is also the
state gemstone for
Conclusion
In
conclusion, amethyst is a wonderful gemstone. Its brilliant color accompanied
by its abundance and low cost makes it an affordable treasure for rock hounds
everywhere. Although it may not really prevent people from becoming intoxicated
or sharpen their wit for that matter, it is still very fetching as a neck
ornament or piece of interior decoration. Whatever form of admiration necessary
amethyst is able to oblige.
Works Cited
http://www.answers.com/topic/amethyst
http://www.bernardine.com/gemstones/drusy.htm
http://en.wikipedia.org/wiki/Amethyst
http://www.galleries.com/minerals/gemstone/amethyst/amethyst.htm
http://www.gemland.com/arizonagems.htm
http://www.gemstone.org/gem-by-gem/english/amethyst.html
http://www.jewelrysupplier.com/2_amethyst/amethyst_properties.htm
http://www.scstatehouse.net/studentpage/gem.htm