Gems

Gems have always had a special fascination for mankind. Forthousands of years, gems were worn as charms, or amulets, to protect people form demons and diseases. Some gems were believed to have the power of enabling their owners to foretell the future. Other gems were supposed to be able to tell whether a person was guilty or innocent of a crime.

In ancient times, gems were distinguished only by their colors. The name "ruby" was given to all precious stone of a red hue. All green stones were called "emeralds." And all those of blue were called "sapphires."

Later on it was discovered that some gems were harder than others and endured longer. So it came about that the value of a gem depended not only on its color, brilliancy, and rarity, but also on its hardness. Diamonds for instance, are today considered the most precious of gems because, besides their beauty, they are the hardest of all stones.

All the gems are called "precious stones." But strictly speaking, the word "precious" is used only for the four most valuable stones, the diamond, the ruby, the emerald and the sapphire. The other valuable stones are "semi-precious,"and these include opals, amethysts and topazes. Many of the precious and semi-precious stones are close relations.

The diamond, the most precious gem, is also the simplest. It is composed of one element, pure carbon. Rubies and sapphires are varieties of a substance called "corundum". Rubies have their carmine color because of small quantities of iron in the corundum. And the presence of various oxides make sapphires bright blue or velvet blue.

A great many of the most beautiful gems are made of combinations of a substance called "silicate." Topaz and tourmaline are members of the silicate group. Garnets and jade are also silicates. Some of the less costly gems belong to the quartz group, which is pure silica. A methyst is one of these. The opal is silica containing five to ten per cent of water. The opal, by the way, is one of the few precious stones which are supposed to bring evil to those who possess it. Even today, many people will not wear opals because of this ancient superstition.

Science today is beginning to learn how to manufacture precious stones artificially. This includes diamonds, emeralds, rubies, and sapphires. These are not imitations; they are actually the same as the natural stone, only they are being produced in laboratories!