A brief about semi-precious stones

Semi-precious stones are natural resources like minerals and are also known as fine gems, jewel or gem stones. A gem stone is a piece of crystal which is cut and polished and is used to make jewelry or other embellishments. However, certain rocks or organic material like amber that are not minerals are also used for jewelry and are therefore often considered to be gem stones as well. Gem-stones like emerald, amethyst, sapphire, and ruby are also important from the astrological point of view.
Stones like diamonds, ruby, sapphire and emerald are not semi -precious. The  distinction between precious and semi-precious stones is supposed to reflect the rarity of stones as well as their quality; however, it is not always the case. It is common knowledge within trade insiders that the notion of precious stones was invented just as a marketing gimmick and does not have any bearing on the respective rarity of any stone. A stone like tanzanite, which is classified under the semi-precious category, is actually a very rare stone whose price rockets much more farther than any precious stone.Both precious and semi-precious stones are  classified by their color, translucency, and hardness. An common term for semi-precious gem stones used in art history and archaeology is hardstones.

In modern times, gemstones are identified by gemologists who describe gems and their characteristics using technical terminology specific to the field of gemology. Gemstones are classified into different groups, species and varieties. A single stone can be classified into various categories depending on its color. For example, other aquamarine (blue), red beryl(red), goshenite(colorless), heliodor(yellow), and morganite(pink) are all varieties of the single mineral species beryl.
Gemstones may also be classified in terms of their “water”. This is  recognized as the grading of a gem’s transparency and brilliance. Very transparent gems are considered first water while second or third water gems are those of a lesser transparency.

There is no universally accepted grading system for gemstones. However, a mnemonic device, the “ four Cs” (clarity, color, cut and carats), has been introduced to help consumers understand the factors used in grading of all gemstones. Nowadays, distinction between precious and semi-precious gemstones are no longer made by the gem stone trade. Many gemstones are used in even the most expensive jewelry depending on the brand name of the designers, fashion, trends, market supply, treatments, etc. Rare or unusual gemstones, generally meant to include those gemstones which occurs so infrequently in gem quality that they are scarcely known except to connoisseurs include andalusite, axinite, cassiterite, clinohumite and red beryl.

Gem prices can fluctuate heavily or can be quite stable. In general, per carat prices of larger stones are higher than those of smaller stones but popularity of certain sizes of stone can affect prices. Prices of gem stones are increasing rapidly with time . Typically, prices range from US$1/carat for a normal amethyst to US$ 20,000 – 50,000 for a collector’s piece.
A few gemstones are used as gems in the crystal or other form in which they are found. Most of the gemstones are cut and polished for use of making  jewelry. Thailand is a popular destination for gemstone cutting. There, the stones are cut into a design and are polished to make the gemstones look beautiful and shiny. Gemstones are often treated to enhance the color or clarity of the stones. Depending on the type and extent of treatment, a stone’s value can improve or deteriorate. Some  treatments are used widely because the resulting gem is stable, while others are not accepted commonly because the gem color becomes unstable and may revert to the original tone.

Some gems stones are manufactured to imitate others gemstones. The imitations copy the look and color of the real stone but posses neither their chemical nor physical characteristics. However, lab created gemstones are not imitations. They tend to have a more vivid color to them, as impurities are not present in a lab-manufactured stone.
Whatever be the case, semi-precious or precious stones will remain fascinating specimens of the nature’s bounty that humans will lust after. The beauty of these fantastic gems will always lead humans to bead them in their jewelry or embellish in their clothing.