Gemstones is God Gifted precious thing to Human being, people like gemstone because of it's beauty. They have been held in high esteem throughout history by all societies in all parts of the world. The histories of certain individual gemstones can be traced over a span of centuries, and gems have the same associations of wealth, prestige, status, and power as gold and silver. In the earliest periods of civilization, people became curious about natural objects, including minerals. Minerals are naturally occurring inorganic chemical elements and compounds. Scientists today have amended this defi- nition in light of discoveries about the arrangements of atoms in crystals. A mineral species is therefore also defined in terms of a definite crystalline structure. The chemical composition of a mineral may vary but only within defined limits. If the composition varies outside these defined limits, the mineral may be given a new name and considered a distinct species. Early humans discovered pebbles and fragments of various brightly colored minerals in fields and stream beds, on mountain slopes, and in barren deserts. Some of these were made into ornaments. Others were ascribed mystical powers or symbolic religious significance. For centuries gem materials held a position of tremendous influence in human affairs. However, there was no science of gemology. The primary attribute of any gemstone was color, yet no reliable ways existed for differentiating minerals of the same or similar colors. It is not surprising
that confusion reigned in both the literature and the marketplace. There are literally hundreds of references to gemstones in the Bible. Yet in many cases it is not known today exactly what stones were being described.
Some incorrect names that were in use nearly two thousand years ago are still employed today! The modern science of gemology is a relatively recent development. Fairly accurate methods of chemical analysis existed more than one hundred years ago. Yet even as recently as 1910 the nature of the internal structure of crystals was not firmly established. When X-rays first revealed the magnificent atomic geometry of crystals in the years following 1914, mineralogy, chemistry, and gemology all entered a new age of sophistication. Progress, however, often adds complications and problems. At the same time that some scientists worked to improve identification methods, others developed ways of duplicating nature s gem masterpieces in the laboratory. Accurate detection technology was, in a sense, developed just in time to prevent collapse of the market for various gemstones. A large part of the value of a fine gem lies in its scarcity as a rare natural object. People are therefore less likely to spend a large sum of money for a stone that might turn out to be a laboratory product. The overall question of the reasons for the value of gems is complex and will be discussed in following pages. Gemology, in the last decades of the twentieth century, is at a major turning point in its growth. Worldwide affluence has created an unprecedented demand for gems of fine quality, vastly raising their cost. Political problems in gem-producing areas have created restric- tions in the supply of gem materials, further raising gem prices. Synthesis technology is developing new materials with very desirable properties that are never found in nature, as well as laboratory equivalents of the more valuable natural gemstones. It has become essential to devise ways to distinguish natural and synthetic materials as well to as reveal simulations and methods of color enhancement by chemical and physical treatment. This book is an encyclopedia of gemstones. It is an attempt to provide basic information about all the mineral species that have been cut as gems, including their color varieties. This introduction must first, however, speak to the most basic question at hand: What is a gem?