The chemical formula of  mineral Beryl is indicated by Be3Al2(SiO3)6 or Beryllium Aluminum Silicate. Beryl is actually a Silicate mineral. The Silicates is considered as the largest and the most complicated class of minerals. They are also the most interesting mineral class comprising wonderful and attractive mineral specimens, which are exhibiting splendid microscope views in both transmitted and reflected light. Some geologists made estimation that about 90 percent of the Earths crust is actually made up of silicates. It has been known also that approximately 30 percent of all minerals are silicates. It is not surprising to know that silicate occurs in great abundance since oxygen and silicon are popularly known as the two most abundant elements in the Earth’s crust. Silicates have the basic chemical unit of SiO4 tetrahedron shaped anionic group with a negative four charge. In the chemical structure of Silicate, it can be found that the central silicon ion has a positive four charge while every oxygen has a negative two charge. Thus, each silicon-oxygen bond in the chemical structure is equal to one half of the total bond energy of oxygen. This chemical structure condition of silicates leaves the oxygen with the option of bonding to another silicon ion and therefore linking one SiO4 tetrahedron continuously from one to another. Silicates actually possess a complicated chemical structure formed by silicate tetrahedron, which is considerably and truly amazing. They can be found forming as single units, double units, sheets, chains, rings and framework structures. These different ways of combinations that produce different types of structure formations actually makes the Silicates class the largest, the most complicated and the most interesting mineral class. Beryl is a ring silicate, the silicate tetrahedra that are linked to form rings.

 

            Mineral Beryl is considered as one of the most important gem mineral in the mineral world and most especially among serious mineral collectors. This remains true despite the fact that Beryl mineral is often regarded unknown to the general social public and even in the gemstone buying public. The name of the mineral species Beryl is derived from the Greek word beryllo, which means precious blue green color of seawater. Beryl has been considered as gemstone since prehistoric times. Beryl minerals are commonly associated with other interesting minerals such as quartz, tourmalines, euclase, micas, calcite, and some feldspar. Beryls are commonly used as gemstones and also as mineral specimens. Beryl contains the element beryllium, thus it is also used as source of beryllium. Treating the stone with oil can mask internal flaws in beryl gems. Unscrupulous dealers will often apply this treatment to a stone without informing the buyer. A pure Beryl mineral is colorless in appearance. This Beryl variety usually allows the whole constituent of white light to pass through making the mineral non-pleochroic even between crossed nicols of petrographic polarizing microscope used in the field of optical mineralogy. If Beryl happens to appear in various colors or shades when viewed under a polarized microscope for mineralogists, this varied coloration is brought about by many impurities present in the chemical composition of mineral Beryl. These splendid color varieties of mineral Beryl make it an interesting gemstone, which exhibits splendid microscope images under gemological polarizing microscope. Without these fascinating colors and different shades exhibited by the mineral, Beryl would turn out to be a rather ordinary and unattractive gemstone with only average brilliance and fire when viewed with the aid of gemological polarizing microscopes.

 

There are different names applied for the different color varieties of mineral Beryl. The green variety is called Emerald. This Beryl variety displays fascinating green color in transmitted light of gemological microscope. The green color exhibited is by minute amounts of chromium present in its chemical structure. The blue variety is called Aquamarine. This blue variety of Beryl displays splendid microscope image in transmitted light of polarized light microscope for geologists and also under gemological microscope. The greenish-yellow variety is called Heliodor. Its color is due to the presence of Fe O charge transfer and rarely due to Uranium. It has fantastic color display under gemological microscope. The pink variety is called Morganite. Its color is due to the presence of manganese (Mn). The colorless variety is called Goshenite. The red variety is simply called red beryl and the golden variety is also called golden beryl. Emerald and Aquamarine are the two varieties of Beryl mineral, which are regarded very popular in the gem world. All varieties are producing brilliant and marvelous images when viewed under gemological microscopes. The rest of the varieties mentioned are also used as gemstones but are not as well known.

 

            The highly prized Beryl mineral variety is the Emerald gemstone. It is one of the most valued gemstones in the gem world. The green color of Emerald is considered peerless and oftentimes, all other green colored gemstones are compared to the intensity of the Emerald stone. More often, Emerald mineral specimens are flawed with mineral inclusions and fractures, which are clearly seen when gem mineral is viewed under a polarizing light microscope for geologists. These flaws are actually considered as part of the Emerald’s character, which is very unlikely to that of the other gems. These flaws are considerably helpful for they are used to determine natural from synthetically produced stones. Emerald stones, even low grade, when cut as gems carry a high price in the mineral markets. This is why uncut specimens of emerald are considerably rare on the mineral market. True Emerald specimens in matrix are especially hard to find. Most commonly, those that are seen in the mineral markets sold with a highly inflated price that are in matrix form are fakes. These are actually the natural crystals of Emerald, which are glued into a host rock and then sold as in matrix specimen.

 

            Aquamarine, the blue variety of beryl is also considered popular in the gem world. Even though considered as a popular gem, Aquamarine does not command a high price. There are plenty of uncut Aquamarines and those that are cut as gems in the mineral markets. Both cut and uncut materials are found exhibiting interesting brilliant stone image under petrographic polarizing light microscopes. They can be found in a relatively expensive price but not as high as that of the Emeralds. Aquamarine in large crystals can be possibly found available in the open market. Perhaps, they can be regarded to represent the largest raw gemstone specimens.

 

            Mineral Beryl commonly occurs in veins. They are usually found forming in hydrothermal veins and in pegmatites. They can be also found with feldspar and quartz. Beryl is found most commonly in granitic pegmatites. It also occurs in mica schists in the Ural Mountains. Best field indicators of mineral Beryl commonly include hardness and color, crystal habit and lack of good cleavage. Mineral Beryl has notable occurrences in types of localities that include California, Brazil, Africa, and many other localities for other beryls. Some areas are also included like Brazil, Russia and Pakistan for aquamarine. Colombia and some African localities for emerald are also considered. Beryls can be also found in some European countries such as Germany, Austria and Ireland. Morganite can be found in Madagascar.