Background:
First discovered
in the Ural mountains of Russia
in 1830 on the 12th birthday of
Czar Alexander II, hence the name.
Chemical Formula:
BeAl2O4
- Beryllium Aluminum Oxide
Species:
Chrysoberyl
Specific Gravity:
3.70-3.76
Hardness:
8 1/2
Refractive Index (RI):
1.74-1.76
Birthstone for:
Alternate birthstone for June
Color(s):
In its finest qualities,
alexandrite changes in color from
green in sunlight (ultra-violet
light), to purplish-red under
incandescent lighting (light bulbs).
Where Mined:
Brazil and Sri Lanka are the most
important sources of chrysoberyls.
Deposits are also found in Russia,
Tanzania, Zimbabwe, Madagascar
and Myanmar (Burma)
Enhancements:
none
Care:
normal
Notes:
Very scarce especially
over 1.50 carats.
Price:
As expensive as diamonds. Don't
expect to find natural alexandrite
in your local jewelry store, it's
very rare. If you do see it for
sale, the colors are likely to
be grayish green and brownish
purple or lavender. Prices for
natural alexandrites that show
a noticeable change of color start
at about $1,500 per carat retail
and go over $20,000 per carat
depending on size and quality.
The distinctness of the color
change and the color intensity
are the most important price factors,
but size and clarity also affect
the cost.
Look for:
Strong color change from green
to red without showing browns.
Background:
Quartz may be the oldest gemstone
known to man. In Europe, rock
crystal objects have been unearthed
with the remains of prehistoric
man (20,000 BC). Archaeologists
have found amethyst beads, seals
and good luck charms in Egypt
which date back before 3100 BC.
When quartz crystals are squeezed,
they become electrically charged.
When an electrical current is
run through a piece of quartz,
the crystal vibrates at a single,
constant frequency which is determined
by the thickness of the crystal
and the strength of the current.
This is why synthetic quartz are
used to regulate watch movements
and the electric frequencies of
radios.
Chemical Formula:
SiO2 - Silica (crystallized
quartz)
Species:
Crystallized quartz
Specific Gravity:
2.64-2.66
Hardness:
7
Refractive Index (RI):
1.544-1.553 (very constant)
Birthstone for:
February, and 6th wedding anniversary
stone
Color(s):
Purplish/Violet available in light
to dark tones.
Where Mined:
Major sources are Brazil, Uruguay,
Bolivia, and Zambia.
Enhancements:
Routinely heated to lighten its
color and remove smokey areas.
Care:
May fade from heat treatment or
long exposure to sunlight (including
tanning beds).
Pricing:
Due to their abundance, quartz
gemstones are quite affordable
and should be inexpensively priced.
Amethyst, which is the most expensive
variety, might retail from $2
to $90 per carat, depending on
quality and cut. The most expensive
color is an intense, deep, evenly
colored purple with flashes of
red under incandescent light,
and the least costly is pale lavender.
Look for:
Stones without any eye visible
inclusions.
Background:
The name aquamarine is Latin origin
meaning sea water in allusion
to its color. Traditionally, aquamarine
has been used as a charm by sailors
for protection while at sea. It
also is believed to preserve and
enhance mutual love to maintain
a good marriage, and to ensure
truth in relationships and business
dealings.
Chemical Formula:
Be3Al2(Si6O18)
- Beryl
Species:
Cyclosilicates
Specific Gravity:
2.68-2.80
Hardness:
7.5-8
Refractive Index (RI):
1.563-1.583
Birthstone for:
March
Color(s):
Light blue to bluish green
to deep blue
Where Mined:
Brazil, Zambia, Mozambique, Angola,
Nigeria
Enhancements:
Routinely heated to remove yellow
areas
Care:
Normal
Notes:
Blue topaz can be an inexpensive
alternative
Pricing:
Should be moderately priced.
Look for:
Eye clean stones in any sizes.
Background:
Its name is derived from
the French word for lemon - Citron.
Chemical Formula:
SiO2 - Silica (crystallized
quartz)
Species:
Crystallized quartz
Specific Gravity:
2.64-2.66
Hardness:
7
Refractive Index (RI):
1.544-1.553 (very constant)
Birthstone for:
Alternate Birthstone for November
Color(s):
Lemony yellow to deep oranges
Where Mined:
Brazil
Enhancements:
Routinely heated to increase the
golden hues.
Care:
Normal, but can fade in prolonged
exposure to sunlight and tanning
beds.
Notes:
Starts out as amethyst and is
heated to change the color.
Pricing:
It sells for $2-$60 per carat.
Look for:
Eye clean stones
Background:
Emeralds have been cherished
for as long as there has been
a written history. Archaeologists
evidence indicate that emerald
deposits in Egypt may have been
exploited as early as 3500 BC.
However, most of these stones
at that time were pale, and
heavily included and flawed.
It wasn't until the 1500's,
when the Spanish invaded the
Americans, that Europeans realized
the beauty of emeralds and vast
quantities of Colombian emeralds
were brought to Europe by the
conquistadors.
Chemical Formula:
Be3Al2(SiO3)6
- Beryllium aluminum silicate
Species:
Beryl
Specific Gravity:
2.67-2.80
Hardness:
7 1/2-8
Refractive Index (RI):
1.57-1.60
Birthstone for:
May and 20th and 35th wedding
anniversary stone
Color(s):
Greens with yellow to bluish
overtones
Where Mined:
Africa and Brazil
Enhancements:
Routinely oiled to improve color
and clarity appearance. Commonly
filled to smooth fractures the
break the surface. Occasionally
dyed to enhance the color.
Care:
Avoid big temperature changes,
ultrasonic cleaners, chemicals
and steam cleaning as they can
easily affect the enhancement.
Notes:
Since emeralds are virtually
always enhanced with oils of
both natural and synthetic types,
in smaller sizes don't be too
concerned. If you're spending
thousands for a larger emerald,
than whether or not it is enhanced
and how is a fair question.
So is, how "permanent"
is the enhancement. A qualified
appraiser would be in order
and recommended for your protection.
Pricing:
Huge variances depending on
the color and clarity. Prices
range from moderate to expensive.
If a 1ct. emerald has a saturated
green color and is transparent
and eye-clean, it can be worth
over $5000 retail. Top quality,
6ct. emeralds can wholesale
for over $10,000 per carat!
Emeralds which are light green
and have poor transparency,
are not worth much, no matter
how they are labeled.
Look for:
Stones with eye visible inclusions
are normal, so try and minimize
them. Avoid stones with large
feathers or cracks flowing from
one side to the other as that
might affect the durability.
Also watch out for opaque stones
as they are lifeless.
Special Note:
Consider "Created"
emeralds which are of the same
chemical composition as natural
ones, but are "lab grown"
versus mined from the ground.
These created gems are available
in brilliant colors and very
clean making them durable and
affordable. See Chatham Created
Emeralds in jewelplus.com online
catalog.
Background:
The word garnet comes from the
Latin granatum meaning seedlike.
Garnet crystals in rock resemble
shape and color of pomegranate
seeds. Historical accounts and
finding suggest that garnet
beads and inlaid jewelry were
worn in Egypt as early as 3100BC.
Tracing the history of gemstones
is difficult because they were
often misidentified. It is certain,
though, that during the 18th
and 19th centuries, garnets
were popular in Europe.
Chemical Formula:
Ca3A12(SiO4)3
- Beryllium aluminum silicate
Species:
Andradite, Spessartine, Almandine,
Pyrope, Grossular
Various members of garnet family:
Demantoid (green), Topazolite
(yellow/orange), Melanite (black),
Kashmirine (orange), Little
Three Mine (orange), Mandarine
garnet (orange), Rhodolite (purple-red/pink),
Mali garnet (green or yellow),
Hessonite (orange or yellow),
Tsavorite (green)
Specific Gravity:
3.60-4.20
Hardness:
7-7 1/2
Refractive Index (RI):
1.73-1.87
Birthstone for:
January and 2nd wedding anniversary
stone
Color(s):
Almandite garnet is a rusty,
orangy color. Traditionally
people have considered garnets
to be red, but they can also
be various shades of green,
yellow, orange, brown, pink
or purple.
Rhodolite garnet ranges from
pink to purplish red, and is
mined in Africa, India, and
Sri Lanka.
Tsavorite is a bright yellow
green to grass green, and is
mined in Tanzania and Kenya.
Demantoid garnet is a bright
green, available only in small
sizes and is extremely hard
to find.
Malaya garnet ranges from orange
to gold and is mined in Tanzania
and Kenya.
Pyrope garnet is a very saturated
red, Small pyrope garnets found
in Arizona are called anthill
garnet because they are mined
by ants, who carry them up when
they are excavating their anthills.
Spessartite garnet from Namibia,
is a bright orange and called
mandarin garnet because its
color is a true orange.
Hessonite and Spessarite garnets
mostly come in golds and oranges
and browns that are sometimes
called cinnamon garnets.
Grossular garnet is found in
pale pinks and greens and yellows.
Enhancements:
None
Care:
Normal
Pricing:
For the most part moderate to
inexpensive.
Notes:
Tsavorite is a great alternative
stone for emerald.
Look for:
Clean stones with bright colors.
Inexpensive to moderately priced.
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Largest variety of jewelry & watch designs
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