What is Gemstone

“Diamonds are a girl’s best friend,” was popularized by Marilyn Monroe as a symbol of love and riches. But long before the movies, the early kingdoms of the world, were enhanced by the riches of the crown jewels. The sparkle and brilliance of rubies, sapphires, and emeralds  embedded in gold was the essence of power.  The King and Queen’s crown, was adorned with jewels and the symbol of their rule. The more jewels a kingdom  possessed the more influence they had. But do gems really have power or is it just an illusion? Before we understood how gems were formed scientifically, it was easy to mistake gems as “gifts from gods.” Gems were rare to find and the people who owned them were perceived to hold supernatural powers.

Gems are an oddity of nature. Throughout the ages humans have attributed special significance to gems and the jewelry they made from them. Charms made from gems, were thought to prevent evil from entering your body. Every month has a birthstone to provide good luck to its wearer. Beads, necklaces, earrings, and bracelets were all created to display gemstones. Today gems are pretty to look at and are durable, but humans place the value on them depending on the fashion of the time. For example, in Renaissance times, green turquoise was greatly admired and cost more than other varieties. Today the blue turquoise is fashionable and has more value. In ancient Greece, only blue gems were valued, while in ancient Rome, green gems were prized.

A gem can be organic or inorganic, natural or human-made.They can be minerals, rocks, or anything that has been given monetary value. Only about 80 minerals are considered gemstones, and probably only about 30 are commonly found in jewelry stores. Examples of mineral gemstones include garnet, hematite, and diamond.
Some minerals are given a specific gem name which is different from its mineral name. For example beryl is the mineral name, while the green variety is called an emerald. Corundum is the mineral name for both sapphires (blue variety) and rubies (red variety).

Some minerals are not minerals because they are organic in nature. A pearl, although mainly calcium carbonate, is produced by a mollusk. Amber, or fossilized tree resin is also considered a gemstone. Other gemstones are really rocks, which are multiple minerals. An example is polished granite or obsidian. Finally, some gemstones aren’t technically minerals because they are amorphous materials or lacking a regular crystal structure. Water within the chemical make-up of opal, creates an unorganized crystal structure. Mineral gemstones form through igneous, metamorphic and sedimentary processes. 

Many gemstones are found in pegmatites which is a vein of concentrated minerals. It usually forms when magma cools inside the Earth’s crust (plutonic). Elements and compounds become concentrated and “squeezed” through cracks of the surrounding cooled rock. Emerald, ruby, gold and silver and many other gems are produced in this way. In contrast, jadeite a beautiful green rock gemstone, and most garnets, are produced by metamorphism (high pressure and temperature). Sedimentary rocks can also produce gemstones through precipitation. Many gemstones composed of quartz, such as amethyst, jasper, agate, and tiger-eye are examples. They form by water circulating just below the surface of the Earth with high concentration of dissolved silica. When the water passes through gaps in the rock, the silica precipitates slowly (hundreds to thousands of years) to form quartz minerals.

Other types of organic gems are all made in a different process. Amber is fossilized resin of ancient trees. It is brown to black and usually includes inclusions of ancient bugs that may have gotten trapped when the sticky resin was hardening. Amber is soft enough to be carved into artistic jewelry. Fossils can be cut into gems to highlight their natural symmetry, like an ammonite. A jeweler can arrange the fossils in a necklace or bracelet to look very fashionable. Coral are animals that produce a skeleton of calcium carbonate. When they die, their skeleton can be carved easily. 

Many forms of coral exist but only high quality red, pink, blue, black and white corals are used in jewelry. A pearl is formed when a particle enters the shell of a Pearl Oyster. The irritation caused by the particle secret calcium carbonate around the particle to ease the irritation. In 3 to 6 years a pearl is produced. How do you value a gem? One factor in valuating gems is its weight. Gem weight is measured and valued in carats. One metric carat equals 0.2 grams (.007 ounces). The word carat comes from carob, a Mediterranean tree whose seed was for centuries the standard for weighing precious stones. The price depends on that particular gem on the open market. There are certain properties that will influence the price. 

The gem is worth more if it is natural versus synthetic. The natural color and how the coloring is distributed throughout the stone in important. If the stones have any flaws or inclusions, that could affect the durability of the stone, the value will decrease. The three main factors on the quality of a gemstones are color, clarity, and color. Color should be determined under normal daylight, fluorescent, and incandescent to notice if there are any changes. The clarity of a gem can be determined by eye examination and by using a 10X magnifier to notice any inclusion or blemishes by looking at all angles of the gemstone. The cut of the stone is determined by its beauty, appeal, and symmetry. The price of the gem increases or decreases in value depending on how a jeweler arranges the gem on a ring, earring, bracelet or necklace.

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