Since ancient times, colored stones have been thought to possess innate magical powers and the ability to endow the wearer with certain attributes. According to legend, emeralds are good for the eyes; yellow stones cure jaundice; red stones stop the flow of blood. At one time it was believed that a ruby worn by a man indicated command, nobility, lordship, and vengeance; worn by a woman, however, it indicated pride, obstinacy, haughtiness. A blue sapphire worn by a man indicated wisdom, and high and magnanimous thoughts; on a woman, jealousy in love, politeness, and vigilance. The emerald signified for a man joyousness, transitory hope, and the decline of friendship; for woman, unfounded ambition, childish delight, and change.

Colored gems, because of the magical powers associated with them, achieved extensive use as talismans and amulets; as predictors of the future; as therapeutic aids; and as essential elements to many religious practices-pagan, Hebrew, and Christian.”

Natural gemstones are found in nature. Laboratory-created stones, as the name implies, are made in the laboratory. These stones, which also are referred to as laboratory-grown, {name of manufacturer} – created, or synthetic, have essentially the same chemical, physical and visual properties as natural gemstones. Laboratory-created stones do not have the rarity of naturally colored stones and they are less expensive than naturally mined stones. By contrast, imitation stones look like natural stones in appearance only, and may be glass, plastic, or less costly stones. Laboratory-created and imitation stones should be clearly identified as such.

Gemstones may be measured by weight, size, or both. The basic unit for weighing gemstones is the carat, which is equal to one-fifth 91/5th) of a gram. Carats are divided into 100 units called points. For example, a half-carat gemstone would weigh .50 carats or 50 points. When gemstones are measured by dimensions, the size is expressed in millimeters (for example, 7×5 millimeters).

Gemstone treatments or enhancements refer to the way some gems are treated to improve their appearance or durability, or even change their color. Many gemstones are treated in some way. The effects of some treatments may lessen or change over time and some treated stones may require special care. Some enhancements also affect the value of a stone, when measured against a comparable untreated stone.

Jewelers should tell you whether the gemstone you’re considering has been treated when: the treatment is not permanent; the treated stone requires special care; or the treatment significantly affects the value of the gemstone.

Some common treatments that you may be told about and their effects include:

* Heating can lighten, darken or change the color of some gems, or improve a gemstone’s clarity.

* Irradiation can add more color to colored diamonds, certain other gemstones and pearls.

* Impregnating some gems with colorless oils, wax or resins makes a variety of imperfections less visible and can improve the gemstones’ clarity and appearance.

* Fracture filling hides cracks or fractures in gems by injecting colorless plastic or glass into the cracks and improves the gemstones’ appearance and durability.

* Diffusion treatment adds color to the surface of colorless gems; the center of the stone remains colorless.

* Dyeing adds color and improves color uniformity in some gemstones and pearls.

* Bleaching lightens and whitens dome gems, Including jade and pearls.

In this day and age, gemstones are generally worn for their natural beauty or as a fashion statement, but there are many that “buy-in” to the mythical and mystical symbolisms of gems as well. Whatever a persons reason, the world of gems today offers an almost endless choice. Many new gems have been discovered and are widely available in reds, blues, greens and many unusual shades as well.

Gemstone has two name, one is precious stone, another is semi-precious stone, which is because of the different definitions which can change over time and vary with culture, it is really a hard matter to decide and determine what the different constitutes of the stone. It is used to make jewelry or other adornments. Most gemstones are hard, but some soft minerals have good lustre or other physical properties, so they are used in jewelry to get an aesthetic value. Gems are characterized from the aspects of refractive index, hardness, cleavage, dispersion, specific gravity, fracture, and lustre.

Color is the physical characteristics of a valuable stone, and another determining factor of the value of a gemstone is called water. Water is an archaic term that refers to the combination of color and transparency in gemstones.

But nowadays people do not make the value distinction by the mineral variety in the trade. Depending on the brand name of the designer, market supply, fashion trends, treatments etc., many gemstones are used in the most expensive jewelry. However, no matter how expensive the gemstone jewelry is, diamonds, rubies, sapphires and emeralds still have a higher reputation and almost exceed those jewelry with other gemstones.

The gemstone is well-known as rare and unusual stone, which means it is infrequently and high quality. They are nearly known and distinguished except the experts.

Aside from the diamond, the ruby, sapphire, emerald, pearl (though it is not a gemstone, but always belongs to jewelry) and opal are considered to be precious at first. Later up to the discoveries of bulk amethyst in Brazil in last two centuries, amethyst was considered a precious stone as well, which can be going back to ancient Greece. In the last century, some stones such as aquamarine were very popular and regarded as precious stone as the same.

The price of gemstone is fluctuated sharply and changeable easily, but also can be stable at a firm level. The former one is usually the normal jewelry with gemstone, the latter one is mainly the jewelry such as diamond. Generally the price of larger stone per carat is higher than the smaller stone even chippings. It is a good thing to know more about the jewelry or gemstone, when you want to buy a gift to send to someone, you can choose better one.