Gemstones are generally minerals that have been, or may be,
fashioned to use for personal adornment. As a rule,
gemstones
are beautiful, rare, and durable. Most are minerals: natural, inorganic
materials with a fixed chemical composition and regular internal
structure. A few gemstones
like Amber and Pearl come from plants and animals and are called organics. To be regarded as a gemstone, a mineral (or occasionally an organic material) must be beautiful, most importantly in its color. A gemstone must also be durable - hard enough to survive constant use or handling without becoming scratched or damaged. Finally, gemstones must be rare, because its very scarcity endows it with a greater market value. The mysterious appeal of gemstones, their exquisite colors, and the play of light within them, would alone have made them precious to many. Their rarity, hardness, and durability have made gemstones doubly valuable. The natural beauty, strength, and resilience of gemstones have inspired beliefs in their supernatural origins and magical powers, and gemstones that have survived the centuries have gathered a wealth of history and romance around them.
There are over 3,000 different minerals, but only about
50 are commonly used as a gemstones. Others
are cut for collectors of the unusual, but are often not suitable for wear
because they are too soft and easily scratched. In fact, the number of
minerals regarded as gemstones constantly changes, as new sources and
varieties are
found and fashions
change. Over 130 gem species, including some exceptionally rare stones, are
described in this website, illustrating the very wide range of naturally
occurring gemstones.
THE SCIENCE OF GEMOLOGY
Gemstones are scientifically fascinating, too. Gemologists make a complete
study of each stone, both as it is found in rocks and after it has been
cut and polished. That is why the species entries in
this book show the gem in its rough, natural state, perhaps still embedded
in the host rock (or "matrix"), as well as after it has been cut,
polished, or
carved. Many entries also feature a
micro-photograph which reveals the internal structure of the stone by
magnifying it many times. In this world within a world the gemologist may
turn detective, being able to distinguish between two outwardly similar
gemstones, or between a natural gemstone and a
synthetic gemstones.
Early civilization as far back as the Assyrians (1400 BC) invested rare and beautiful gemstones with magical properties. Some minerals were thought to contain a force or possess certain values and powers. For instance, amethyst was said to prevent intoxication. Tradition associates a gem with each sign of the zodiac based on a color system. Color was thought to unleash the power attributed to the birthstone. In time, birthstones became associated with calendar months rather than the zodiac. And people began to select birthstones in colors other than the original.