TOPAZ
Topaz is
the accepted birthstone for November. Blue topaz is the accepted anniversary
gemstone for
the 4th year; Imperial topaz for the 23rd year of marriage. Citrine is often used an alternative to topaz because
it appears in many of the same colors as topaz. Unlike topaz,
citrine is readily available and inexpensive even in large sizes. In
ancient times just about any stone was likely to be called a Topaz. It is
thought that the word Topaz is either derived from the Sanskrit word tapas
meaning fire or topazioz the Greek word meaning to guess. It has been considered as a symbol of love and affection. The
lore, magic and romance of topaz goes back many thousands of years. It holds
the distinction of
being the gemstone with the widest range of curative powers. The Greeks felt it
gave them strength.
In addition, it supposedly cooled tempers, restored sanity, cured asthma,
relieved insomnia
and even warded off sudden death. Topaz is said to make its wearer invisible in
time of
emergency. It proved the loyalty of associates by changing color in the
presence of poison.
The true topaz is infrequently seen in jewelry stores.
Unfortunately, most people know only the
quartz (citrine) topaz, or glass. In the past almost any yellow stone was called topaz. Topaz
occurs not only
in the transparent yellow, yellow brown, orangy brown, and pinkish brown colors
most popularly
associated with it, but also in a very light to medium red (now found naturally
in fair
supply, although many are produced through heat treatment), very light to light
blue (also often
the result of treatment, although it does occur naturally on a fairly wide
scale), very light green, light greenish yellow, violet, and colorless.
Orange-red "Imperial" topaz and pink colors are rare and most
valuable. Topaz is a hard, brilliant stone with a
fine color range, but it is much more rare and much more expensive than the
stones commonly substituted for topaz. Blue topaz has become very popular in
recent years.
Most of it has been heat treated and/or irradiated to "cure" the
color. It closely resembles the finest aquamarine (which is very expensive
today) and offers a
very attractive, and much more affordable alternative. Silver
Topaz is an eye-clean, colorless, and brilliantly sparkling stone. With its very
affordable price, it offers an inexpensive alternative to the Diamond or white
Sapphire. Sky Blue Topaz, with its light to medium sky blue coloring, has proven to be an excellent substitute for the more expensive Aquamarine.
London Blue Topaz is the darkest of the blue
Topazes and makes an excellent substitute for the more costly blue Sapphire.
Super Blue Topaz is a trade name referring to an intense vibrant blue Topaz. It
is also known as Swiss Blue and Max Blue.
Topaz is found mainly in Brazil, Nigeria, Sri Lanka,
Mexico, Pakistan, USA and China.
TREATMENT: Neutron irradiation and heat
treatment (permanent color)
MOHS HARDNESS: 8 (durable stone but prone to chipping)
CHEMICAL COMPOSITION: A l2 (F,OH) 2 SiO 4
REFRACTIVE INDEX: a=1.606-1.629 b=1.609-1.631 c=1.616-1.638
(The angle light is bent traveling through a gemstone)
DENSITY (SPECIFIC GRAVITY): 3.56-3.57
(The number of times heavier a gemstone is compared to water)
