The World of Prescious and Semi-Prescious gem stones is one of mystery and joy to most people. These gems are the product of the earths growing pains. Many are complex chemical compounds, some single elements. All of these treasures are the product of time, heat and pressure. Most people do not know that the most prized of all of these minerals has been Emerald. The mystique of the Emerald has awed kings and Emperors for centuries. In Ancient Egypt the Pharaohs's prized Emeralds beyond all other stones. The Hebrew priesthood used emeralds in their vestments and as embellishments on religious artifacts. During the Roman empire, emeralds were the most prized gem for the aristocracy. The central and south American Indians prized emeralds as gifts from the gods. The main reason that Diamonds held a place at times above the emerald in value was not due to the relative scarcity of the rough, but due to the relative hardness, Emeralds being 6.7 and Diamonds being 10, meant that it took a great deal of crushed diamond dust to cut and polish diamonds, but far less to cut and polish emeralds. The advent of synthetic diamond abrasives, and some synthetic alternatives have greatly reduced the cost to facet or cab these stones in the twentieth century. Emerald is a member of the Beryl family, which includes Aquamarine, Morganite, Heliodor, Bixbite and Goshenite. These names indicate the color of the crystal. The specific coloring is due to chemical impurities within the crystal structure, and allow for a wide spectrum of variation depending upon the location they are mined from. Emerald is the most difficult crystal to grow in the family, and almost always includes large contaminates, inclusions. The color and clarity of the emerald crystal formed is a factor of the availability of the impurities, the specific temperature, temperature stability during formation, and the pressure during formation. The crystal forms like a snow flake, usually around some other solid in the space, like a tourmaline crystal. As the emerald grows, if the conditions remain perfect, a crystal will grow with perfect color and as clear as glass. This almost never happens, as nature doesn't stay perfect for long. Most emeralds contain a "Garden" and most experts over the centuries have agreed that it is the garden that makes each emerald so prescious, each one is unique. Expecting a perfect emerald is very unrealistic, only available in a synthetic or man made stone. The colored gem stones are classed into three classes, with emerald classed as a type three gem stone. This means that color variations, inclusions, valences, and lack of clarity do not affect the value unless they Jeopardize the structural integrity of the finished stone. Emeralds are priced based upon the source, the origin of the crystal, as this affects the color, and the carat weight. They range from $350.00 per carat to over $20,000.00 per carat retail. The best prices historically going for the Brazilian and North Carolina version, known for their "Coke Bottle" green color. Behind these the most desirable are the Kelly green or the Deep Deep green stones found in Columbia. The major mines in North Carolina ceased producing in the early 1980's, and the Brazilian mines stopped producing in the late 1980's. In the end of 2005 the Brazilian mines were brought back into production. Do not think that a poorly colored or heavily included stone is not as valuable, usually the only issue is the structural integrity of the stone. When selecting an emerald for investment or as a gift for that special person, some good rules of thumb are Color color color. Emeralds are cut to achieve the maximum size finished stone from the available rough, that will be structural sound. This means that the color may or may not be consistent across the entire stone. Again it can not be stressed enough that the two factors that most impact the value of a stone are Color and Carat weight. When shopping ignore any stones that are too "Perfect", as they are likely man made, enhanced, treated or simulant stones. Study any stones you can under the highest magnification you can, the standard in gem stone analysis is 10X magnification, and some classes of stones are graded at 100X. Emeralds are not graded for optical flaws even at 100X magnification, but the specific garden, inclusions or valences, can add to the over all value of the stone. Find the personality of garden you like, the specific shade of coloration you like, and then find the perfect shape and size for your tastes. Enjoy one of natures greatest mineralogical treasures.