Amber is
fossilised tree sap formed millions of years ago and discovered along
the Baltic Sea by Stone Age people. Because it is an organic gem -- one
formed from living organisms -- amber can contain suspended fragments
of animals or plants, making it a true time capsule! Most of us think
of a lustrous reddish gold hue when we think of amber, but it comes in
shades ranging from whites and yellows to reds and browns; its former
prevalence along the Baltic coast of Germany, Poland and Russia earned
it the name "gold of the North." Today's major source of amber is the
Dominican Republic.
Amethyst
Amethyst is
a variety of quartz, is an abundant gem that comes in a range of shades
from pale lilac to deep purple. Because it is so plentiful, amethyst is
also affordable; still, its rich, lush purple -- the colour of royalty
-- has long made it a prized gem in coronation regalia, from the
ancient Greeks and Romans to British royal families. South America,
particularly Brazil, is today's major source of amethyst.
Aquamarine
Aquamarine whose
name comes from the Latin for "sea water," is a member of the beryl
family. Aquamarine crystals usually have excellent clarity, can grow to
very large sizes and range in colour from greenish blue to light
blue-green. Most aquamarine is heat-treated to remove traces of yellow
and intensify its rich blue colour. Brazil is today's major source of
aquamarine.
Blue Topaz
Blue Topaz is
a magnificent gem to include in any collection. Before the 1950s, topaz
was more commonly associated with a yellow or golden gemstone, but with
improved treatment processes, the blue topaz has become one of the most
popular and widely used of all gemstones! Part of its popularity comes
from it's affordability, especially when compared to the cost of other
blue gems like the aquamarine and the sapphire. Another wonderful
quality about the blue topaz is the impressive range of brilliant blues
it comes in. The lightest blue topaz gems are often referred to as Sky
blue topaz, the more pastel gemstones may be called Swiss blue topaz
while the most intense, darkest gems are commonly named London blue
topaz. This plentiful gem is currently found throughout the world
including Brazil, Sri Lanka, Mexico and the United States.
Chalcedony
Chalcedony is
an opaque bluish-white gemstone that is actually a member of the
largest family of minerals on earth -- the quartz family. Chalcedony,
known scientifically as microcrystalline or cryptocrystalline, is a
variety of quartz made up of finely grained microcrystals too small to
be seen by the naked eye. There are hundreds of different chalcedony
varieties that come in an amazing range of colours and patterns. In the
gem trade, the name chalcedony describes only white or lightly coloured
gemstones with a waxy lustre. Collectors and gem dealers call all other
varieties of chalcedony by their particular name. Some of the more
popular varieties include agate, bloodstone (or heliotrope), carnelian,
chrysoprase, jasper, moss agate, onyx, plasma, sard and sardonyx.
Because of its abundance, durability and beauty, chalcedony was one of
the earliest raw materials used by humans in both practical and
ornamental forms. World-wide, there are literally thousands of
localities where fine specimens of chalcedony have been found. Just a
few of these places include Uruguay, Brazil, south-western Africa, and
the Lake Superior area in the United States and Canada.
Citrine
Citrine is
a variety of quartz, is popular for its warm yellow to orange colours
and its affordable pricing. Another one of citrine's assets is its wide
range of sizes -- citrines in 20-carat sizes are not uncommon!
Citrine's versatility and wearability make it a popular choice for
jewellery, either used alone or combined with diamonds or other gems.
Before the development of modern mineralogy, at a time when gems were
identified by colour, Citrine was often mistaken for the similarly
coloured topaz. Its name derives from the Latin word citrus, meaning
"citron." Almost all Citrine is heat-treated to enhance its colour.
Today's sources of Citrine are Bolivia, Brazil and Spain.
Emerald
Emerald is
the most famous member of the beryl family, is prized for its lush
green colour Known as one of the "Big Three" along with sapphire and
ruby, emerald's name derives from smaragdus, the ancient Greek word for
"green." Most emeralds have natural birthmarks (fissures or
inclusions); because of this, they are routinely treated by a process
called "oiling," which means filling fractures that reach the surface
with colourless oils or resins to improve an emerald's clarity and
colour. Colombia is one of the world's largest commercial producers of
emeralds; Colombian emeralds are highly valued for their excellent
colour. Other sources include Zambia, Zimbabwe, Afghanistan, Pakistan,
Brazil and Russia.
Garnet
Garnet is
actually the group name of a gemstone. Named granatus or "seed," by the
Romans because of the stones' resemblance to pomegranate seeds, garnets
come in a wide range of colours, except blue. Pyrope, from the Greek
word pyropos ("fiery-eyed"), ranges from medium to dark reddish orange
to purplish red; the most prized pyrope colour is a glowing red.
Popular with the Greeks, Romans and the Victorians, pyrope is now in
short supply. Tsavorite garnet comes in shades of green; rhodolite
garnet ranges in colour from pink to reddish purple. Modern sources of
garnet are the United States and South Africa.
Jade
Jade may
be either jadeite or nephrite, both gem minerals that are correctly
referred to as jade. The Mayans and Aztecs used jadeite for
ornamentation and for medicine; Spanish explorers called the stone
piedra de ijada -- "stone of the pain in the side" -- after seeing
natives holding it to their sides to counteract aches. From ijada came
the word "jade."
Jadeite
Jadeite comes
in a wide range of colours, from greens and yellows to black and
lavender, and is usually streaked or mottled. The finest quality
jadeite is the vibrant emerald-green variety known as Imperial jade,
named for the royal court of China that once cornered the market on
this precious gem.
Nephrite
Nephrite's colours
range from greens to yellow, brown, black, grey and white; the stone
can be translucent or opaque, is usually mottled or streaked, and is
very affordable and wearable. Nephrite's colours are generally more
muted that jadeite's.
Because
jade is exceptionally tough, it has long been prized by lapidary
artists. It's one of very few gems that can be carved into rings and
bracelets from a single stone, without supporting mountings or
metalwork. In the Stone Age, Chinese workers fashioned nephrite into
tools and weapons. Jade carving is still a national art form in China.
To
improve its colour and appearance, jade is often treated by dyeing,
waxing or bleaching. Jade sources include China, New Zealand, Russia,
the United States, Canada and Taiwan.
Onyx
Onyx is
a variety of chalcedony, is characterised by straight, parallel bands
which are usually black and white. This sturdy stone has long been
popular with gem carvers for creating cameos as well as beads and
cabochons. Modern sources of onyx are Brazil, Uruguay, the United
States and Madagascar.
Opal
Opal is
described as a "phenomenal" gem -- one whose colour defies simple
description because of its many hues and special effects. Opals are
divided into three main categories: white, which have white or light
grey backgrounds; black, with black or dark backgrounds; and fire,
which have red, orange, yellow or brown bodycolors and often don't show
the "play-of-colour" typical of other opals. That flashing
play-of-colour is a result of opal's internal structure: stacks of
sub-microscopic spheres assemble in grid-like patterns, which cause
light to bend and break into the colours of the spectrum. Opals may be
treated by several methods, including oil or wax, to improve
play-of-colour. Australia is a major source for black and white opal --
the gem is the country's national gemstone; Brazil (for white opal) and
Mexico (for fire opal) are other producers.
Peridot
Peridot is
a stone prized for its cheerful green shades, was called "gem of the
sun" by the Egyptians. Its plentiful supply and reasonable cost make
Peridot a popular gem, and its beautiful colour makes it an exciting
contrast when used with other vibrant stones like Citrine and pink
tourmaline. Available in a range of colours from brownish or yellowish
green to greenish yellow, Peridot is mined in Myanmar (formerly Burma),
Pakistan and the United States. Period's name derives from the Arabic
word faridat, meaning "gem."
Rose quartz
Rose quartz is
a budget-wise stone that ranges in colour from very light pink to
medium-dark pink. Because rose quartz often has myriad internal
fractures, the stone may have a translucent, cloudy quality or appear
delicately veined, like jadeite. A durable stone, rose quartz is lovely
when it's fashioned into bead bracelets and necklaces. Brazil and India
are among the sources of rose quartz.
Ruby
Ruby along
with sapphire and emerald, one of the "Big Three" -- is a variety of
corundum, the same species as sapphire. Its very name comes from the
Latin word ruber, meaning "red." Available in a wide range of reds,
rubies are especially prized in the vivid red "pigeon's blood" colour.
Myanmar (formerly Burma) is considered to produce the finest rubies,
but large, extremely fine rubies are rare and prohibitively costly.
Fortunately for consumers, there are ample treatments and sources --
including Afghanistan, Kenya, Sri Lanka and Vietnam -- to make rubies
affordable for most people. Many rubies are heat-treated or
cavity-filled with epoxy resin or glass to improve colour and/or
clarity; such treatments are detectable only to a trained gemmologist.
Sapphire
Sapphire along
with ruby and emerald, one of the "Big Three" -- is a variety of
corundum, the same species as ruby. In fact, if a corundum doesn't
qualify as ruby, it's considered sapphire. Although most people think
of sapphire as blue, it can actually come in colours from violets and
greens to oranges and yellows to pinks and purples. These "fancy"
sapphires include amethystine or plum (purple), golden, white or
colourless, and the vivid padparadscha, which is pinkish orange to
orange-pink. The latter term comes from padmaragaya, the Sinhalese term
for "lotus colour" Heat-treatment to improve colour and/or clarity is
common for blue sapphires. Sapphires can also be partly-coloured,
displaying a combination of colours The sapphire's place as a
favourite gem of royals was reinforced in 1981, when Britain's Prince
Charles presented Lady Diana with an exquisite blue sapphire engagement
ring. Historically, India and Pakistan were the sources of fine blue
sapphire; today, production is limited. A number of countries
world-wide are the modern sources of sapphire, including Australia,
China, several African countries and the United States.
Smoky Quartz
Smoky Quartz is
a durable stone that ranges in colour from light to dark brown, is an
abundant and reasonably priced choice for a wide variety of jewellery.
Smoky quartz may be heated to lighten its colour, or irradiated to
deepen its colour. Once found in the Cairngorm Mountains in the
Scottish Highlands, smoky quartz is a traditional gem there, where it's
still known as Cairngorm. Modern sources for smoky quartz include
Brazil, Switzerland and the United States.
Tanzanite
Tanzanite is
named after Tanzania, the east African country where the gem was
discovered in 1962. Heat-treating the gem produces a range of colours,
from light to dark shades of violet blue to pure blue. Tanzanite also
possesses a quality called pleochroism, which means that it will show
different colours when viewed from different directions; with
tanzanite, the colour spectrum will be shades of purple and blue. To
date, Tanzania is the only source of this gem.
Topaz
Topaz comes
in a wide range of colours, from colourless to blues, reds and purples,
including the shades of brown that many consumers recognise. Topaz is
usually named for its colour, such as blue topaz or pink topaz. Special
trade names include imperial topaz, an expensive variety in shades of
medium reddish orange to orange-red, and sherry topaz, with its
yellowish brown or brownish yellow to orange shades. Consumers
sometimes confuse Citrine or smoky quartz with topaz; the name itself
probably comes from the old Greek name Topazios (now Zabargad), a Red
Sea island which once produced Peridot, which was mistaken for topaz.
Topaz varieties can come in very generous carat sizes -- the
Smithsonian Institution houses the "American Golden," a light yellow
topaz that's a whopping 22,982 carats! Common treatments for topaz are
heat, which can change some yellow or brown gems to pink, and
irradiation and heat, which produces most medium- to dark-blue topaz.
Modern sources of topaz include Australia, Brazil, Mexico and the
United States.
Tourmaline
Tourmaline comes
in such a wide range of colours that it's truly one of nature's most
versatile gems. Before the development of modern mineralogy, at a time
when gems were identified by colour, tourmaline was often mistaken for
another gem such as emerald or ruby. The name tourmaline itself comes
from the Sinhalese word toramalli, meaning "mixed gems." Tourmaline
exists in a range of shades within its many colours Tourmaline
varieties include rubellite, in pink to red shades; indicolite, in dark
violet blues to blue and greenish blue; Paraíba tourmaline, named for
the state of Paraíba, Brazil, in intense shades of violet-blue to
greenish blue and blue; the intensely green chrome tourmaline;
partly-coloured tourmaline, with its combination of colours, the most
common of which is green and pink; and watermelon tourmaline, which
displays a pink centre rimmed by green. Tourmaline's colour is often
enhanced through heat or irradiation. Today's major source of
tourmaline is Brazil.
