| THE LORE It is axiomatic,
that the longer a mineral is known, the greater number of
names it accumulates. Beryl (pronounced barrel) is one of the
oldest known minerals, and over several thousands of years it
has accumulated an enormous number of terms. However, the term
Aquamarine seems to
be a relatively modern invention. While authors describe this
variety of gemstone, the specific term apparently was first
used in an important gemological work by Boetius de Boodt in
his Gemmarum et Lapidum Historia. (1647). After
this appearance it quickly established itself as an accepted
varietal name.
Aquamarine through the ages has thought to confer dignity,
be symbolic of charity and purity, improve memory, impart
wealth, protect against dangers and illness while at sea,
avert ambushes, cure shortness of breath, and many other
advantages. It also became an appropriate morning gift from a
bridegroom to his bride on the day after their wedding. If
held in the mouth it enables one to call upon any elemental
power and receive satisfaction for any question asked.
THE COMPOSITION: Aquamarine belongs to
the Beryl family. This is the same group that
provides us with Emerald, Golden Beryl, Morganite &
Goshenite. The rough is usually formed in prismatic elongated
crystals often etched or striated. For this reason, the larger
the gemstone, the more likely it will not be calibrated.
Rather the piece will tend to be elongated or, in the
case of rounds, much more costly if over 8 mm.
Greenish aquamarines are due to iron. But
they lose their green tones when the iron (yellow color
bearing) is burned out. Blue aquamarines owe they're
color to heat treatment of green aquamarine. Therefore, most
Aquamarines have been heat treated. If your
customer should happen to bring up the subject of treatment
you can point out the great advantage of the treatment. That
is, there are gas bubbles in some natural rough that later may
explode at temperatures as low as 100 degree F. Thus, an
untreated Aqua may later develop an inclusion from exposure to
heat, such as steam cleaning. However, any heat treated rough
with inclusions will have exploded and been discarded. The end
result of what you are showing your customer is a beautiful
blue, durable, gemstone suitable for everyday wear.
LOCALES: The finest Aqua still come
from Brazil, where there are many important deposits--and from
PSU!
Any discussion of Brazilian Aqua deposits must
concentrate on one or two of the most important sites, because
at any one time there may be many small mines in operation. So
let's talk about the northern part of the State of Minas
Gerais (General Mines). All deposits are pegmatitic in origin.
Production peaked in 1981 and has been falling ever since. The
expense of finding and working new areas is considerable, so
it is unlikely that Aquamarine will ever flood the market.
Mobs' hardness: 7-8.0 Specific gravity:
2.67-2.71 Refractive index: 1.577-1.583 |
