The Mineral & Gemstone Aquamarine
PHYSICAL PROPERTIES:
Chemistry: Be3A12(Si
Composition: Beryllium Aluminum Silicate
Class: Silicates
Subclass: cyclosilicates
Crystal system: hexagonal; 6/m2/m2/m
Fracture: conchoidal
Hardness: 7.5 - 8.0
Specific Gravity: 2.68 - 2.80
Refractive Index: 1.563 - 1.583
Pleochroism: distinct in deep colors
Streak: White
Luster: vitreous, some have chatoyancy (cat's-eyes and stars)
Color: blue to blue-green to sea-green
Cleavage: imperfect
Transparency: transparent to translucent
Associated
Minerals: tourmaline, some feldspars,micas,euclase,calcite,quartz
COMPOSITION:
The color of Aquamarine is due to trace amounts of iron impurities in
the beryl structure. The color ranges from pale green to pale blue to
blue depending on the concentration of the iron and where the iron impurities are located within the beryl crystal structure.
DISTINGUISHING
CHARACTERISTICS:
Modern methods have made it possible, and very common, for aquamarine
to be heat-treated to drive the green out of the stone and leave a more
pleasing darker blue. Irradiation can reverse this process. Restoring
the yellow and green colors. Usually it takes a stone of some size to
hold the darker shade.
This is a permanent treatment and has become accepted in the jewelry industry.
It seems that
a darker pure blue has become desirable these days. But if you are someone
who prefers the natural slightly green gems, knowing that they haven’t
been heat treated. You will find that these stones are less expensive.
At this particular point in time.
ENVIRONMENT:
Aquamarine occurs primarily in granite pegmatite's and to a lesser extent
in granite vugs. It is also in hydrothermal carbonate veins and greisens.
Aquamarine is typically associated with quartz, feldspars and muscovite,
and often occurs with other common pegmatite minerals such as biotite,
garnet, phenakite and topaz. Because of aquamarine's relatively high hardness
and specific gravity, it is sometimes found in eluvial and aluvial deposits
CRYSTAL DESCRIPTION:
Aquamarine is found in incredible sizes and quality. Gems have been cut
that weigh several hundred carats, way too large to be worn. Due to this,
the price of aquamarine doesn't vary in sizes above one carat. A 50ct.
Aquamarine will be worth the same price per carat as a one carat gem of
equal quality. The price is dependent on its clarity, the depth of color
One of the largest known crystals, was found in Brazil in 1920. It was
19"long and 16" wide and weighed 243lbs. It was cut into a number
of important gemstones. A 13lb. uncut piece of the green outer portion
of the crystal resides in the American Museum of Natural History. The
British Museum of Natural History owns an 879.5ct. flawless, step-cut
Aquamarine with a lovely sea-green color.
Beryls, and Aquamarine in particular, are known for having long, hollow
tubes. This is a distinctive feature and will identify a gem as a member
of the beryl family. If there are enough of these hollow tubes, cat’s
eyes or stars can be produced with proper cutting. Cat’s Eye Aquamarine
is rather rare and even more rare is Star Aqua.
LOCALITIES:
Madagascar was the historical source of aquamarine. Which produced beautiful
medium dark blue stones. Today Brazil is probably the most prolific supplier
of aquamarine. The natural color of Brazilian gems leans toward bluish-green.
Other important sources of aquamarine are the African countries of Tanzania,
Kenya and Nigeria. Also Sri Lanka, Afghanistan, The Ural Mountains in
Russia, Pakistan and India
In the US, Colorado has some high quality Aquamarine. It is found in the
mountain peaks of Mount Antero and White Mountain. We have also seen some
nice Aquamarine come from remote areas of Idaho.
The Gilgit District
in Pakistan is producing many fine collector specimens. Several of these
specimens are featured in our minerals section under of course Aquamarine.
USES:
Gemstones & Mineral specimens
FACTS & HISTORY:
Aquamarine has been credited with providing courage, curing laziness
and quickening the intellect. In the Middle Ages it was believed to give
the wearer both insight and foresight. Along with freedom from insomnia.
Among various peoples, it had the reputation of providing happiness and
everlasting youth. Water in which an aquamarine had been soaked was believed
to cure eye troubles, stoppage of breath and hiccups.
It was also called the treasure of mermaids, with the power to keep sailors
safe at sea. Said to be a particularly strong charm when immersed in water.
Which would be where sailors needed its power most. Aquamarine was also
said to have a soothing influence on land, especially on married couples.
It's power helped husbands and wives work out their differences and ensure
a long and happy marriage. Thus making it a good anniversary gift. Aquamarine
also protects against the wiles of the devil and a dream of aquamarine
meant you would meet new friends.
Aquamarine and Bloodstone are the birthstones for for the month of March It is the anniversary gemstone for the 19th year of marriage.The astrological signs of Aquamarine are Pisces and Scorpio