International Gem Society
Dedicated to bringing quality information and educational services to everyone interested in gemstones.
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WHAT IS A GEM?
... Emerald, ruby, opal, gems and jewels. These words have been in our vocabulary for thousands of years. However, defining what a gemstone is has proven to be a major challenge. Not for everyday people with common sense, but for those lexicographers who have a need to precisely define each work in our language.
by Don Clark CSM
... Most gems are "minerals that have been chosen for their beauty and durability, then cut and polished for use as human adornment." This definition covers the vast majority of the things we regard as gems. The problem is, that for every defining feature, there is an exception.
... Most gems are minerals but some, notably pearls and amber, are organics. That means they were created by living organisms. The coating of a pearl is mineral which is confusing some folks. By definition though, a mineral must be created in the earth. Hence, pearls fall into a different category.
... Amber began life as tree sap. After millions of years it has undergone a transformation into a polymer, a natural plastic. This most definitely isn't a mineral, but it has been regarded as a gem for 1,000's of years.
... The next qualification is that they are chosen for their beauty. It would be redundant to say that beauty is in the eyes of the beholder. There are gems I don't think are beautiful, like the Pepto Bismol pink and olive green of unakite. However, I love some brown gems which are often used in the earth tone jewelry that is so popular today. To other folks, brown is not a beautiful color, bringing up images of dirt.
... Durability is usually a high priority in choosing a gem, but two of histories most popular gems are particularly delicate. Pearls are generally considered to have a life span of about a century. That is because they are soft and the simple act of wiping the dust off of them slowly wears the surface coating away. And woe be to the woman who puts her pearls on before using her hair spray and atomized perfume. These can seriously stain and damage pearls.
... Opals have been one of the most prized gems throughout history, but they are notoriously delicate. They have a water content and as they dry out they may crack. This is usually done before they are cut and put into jewelry, but many a tear has been shed over those that crazed long after they were paid for.
... Opals are also fragile and can break with the slightest bump. Not to mention heat sensitive. I knew one poor lady who had a prized opal set in a brooch, where it wasn't likely to be damaged. One night she wore it to a Christmas party. As she went from the warmth of her house into the cold winter night, it shattered with an audible crack.
... So much for beauty and durability, how about cutting and polishing? Now, more so than a decade or two ago, using whole crystals in jewelry is quite popular. Natures crystals can be exceptionally beautiful and some people believe they have special properties that are enhanced when left whole. So, let's not insist that our gems be cut and polished either.
... The last qualification that is usually associated with a gemstone is that is be used for human adornment. There are about 3,000 minerals that have been cut and polished and admired for their beauty. Of these, only about a hundred show up in jewelry. The rest are simply too delicate to wear well. They are strictly in the domain of the collector.
... I feel sorry for the lexicographers who have struggled to define what a gemstone is. There simply isn't a concise definition that covers all the elements that have been regarded as gems throughout the centuries. For the average person though, you can recognize a gem at first glance! To heck with the definitions, if it makes your eyes light up, it is a true gem!
WHAT IS IT?
...The allure of gemstones is their fantasy of color and light. People have been intrigued by beautifully colored stones since time immemorial. The love of gems hasnít changed, but we now have a very scientific element to contend with. As much as I love the science of gemology, it has the unfortunate side effect of having taken much of the mystique and romance out of our stones.
By Don Clark CSM
... Gemology only became recognized as a science in the 1930's. Up until that time all transparent, red gems were considered rubies, blue ones sapphires and green ones emeralds. Today, as a professional, the only thing I can call an emerald is a crystallized beryllium, aluminum silicate with trace amounts of chromium. Whoopee!
... Today's professionals call beautiful green gems names like tsavorite, tourmaline and diopside. If they look like emeralds to you, that's wonderful! While that may not fit today's precise scientific description, you still have the poetic and romantic sense of the word correct!
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