Precious and Semi-Precious Stones

Women like to wear gemstone jewelry as well as most men. And it's important to know some facts about precious and semi-precious stones before you buy them or just to know something new.

Precious stones are collectible and used in jewelry when they are polished and faced or cut. Gemstones are rocks or minerals which occur naturally directly out of the mine or ground and they are usually the most expensive and popular among consumers and collectors. And precious stones can be laboratory simulated and they are easier to come by and they are less expensive than natural gems.

You can also meet organic precious stones. For example, jet being a form of coal refers to organic precious stones as well as amber which is made from fossilized tree resin. There are also precious stones which can't be used in jewelry because they are too fragile or soft but such gems are sought by collectors and are exhibited in museums because of their beauty.

There are special technical specifications among gemologist for differentiation of precious stones. The first is the chemical composition of a gem. Most precious stones are crystals classified by the crystal system a trigonal, monoclinic or cubic. Gemstones are also classified into groups, varieties and species. The aquamarine, heliodor, emerald and morganite are varieties of the mineral species beryl. And the ruby is the red variety of the species corundum belonging to the hematite or spinel group. Such separation into types of groups helps to identify the color, composition and origin of precious stones. Gems also have dispersion, cleavage, luster, fracture, index, hardness and specific gravity and each of the mentioned features are important in assessing the stone's value.

And what are semi-precious stones? Semi-precious stones are organic compounds or minerals used in jewelry and they differ from precious stones because they are less expensive and more plentiful. A large proportion of the semi-precious stones are of the silicate class of mineral and it composes 90 per cent of the earth's crust.

The main advantage you get with semi-precious stones is that you economize- there are semi-precious stones which can be easily confused with expensive gemstones because they have the same color and other features. Zircon is an excellent diamond substitute while yellow-green peridot and creamy-green jade can be confused with emerald. Topaz is most reminiscent of a sapphire. The blood-red garnet is perfect to replace ruby. But there are also semi-precious stones which are not similarities to the cardinal gemstones. Opal, for example, appears to be blue or pearl-grey but silicate micro-crystals refract the light through the stone in rainbows. There are also semi-precious stones which are not stones, rather organic compounds. For example, amber takes on a magnificent golden brown hue, coral is a pinkish-red gem from the species of coral tree and pearl is harvested from oysters.
Choose your gem according to Chinese horoscope, to gem legends or just because of its color. And enjoy the beauty given us by earth and improved by jeweler designers.