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GEM Software
A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments. Certain rocks (such as lapis lazuli, opal, and obsidian) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) may also be used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some softer minerals such as brazilianite may be used in jewelry because of their color or luster or other physical properties that have aesthetic value. However, generally speaking, soft minerals are not typically used as gemstones by virtue of their brittleness and lack of durability. Found all over the world, the industry of coloured gemstones (i.e. anything other than diamonds) is currently estimated at US$1.55billion and is projected to steadily increase to a value of $4.46billion by 2033. A gem expert is a gemol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardinal Gems
Cardinal gems are gemstones which have traditionally been considered precious above all others. The classification of the cardinal gems dates back to antiquity, and was largely determined by ceremonial or religious use as well as rarity. The term has largely fallen out of use. The five traditional cardinal gems are: * amethyst (purple) – Rare and precious in the Old World until large deposits were found in Brazil. * diamond (transparent) * emerald (green) * ruby (red) * sapphire Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name ''sapphire ... (blue) References Gemology {{gemology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemology
Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a specific interdisciplinary branch of mineralogy. Some jewellery, jewelers (and many non-jewelers) are academically trained gemologists and are qualified to identify and evaluate gems. History Rudimentary education in gemology for jewellers and gemologists began in the nineteenth century, but the first qualifications were instigated after the National Association of Goldsmiths of Great Britain (NAG) set up as an Education Committee for this purpose in 1908. The committee emerged as a distinct branch of NAG (named the Gemmological Association) in 1931, shortly after the incorporation of the Gemological Institute of America (GIA). In 1938 the branch was renamed as the Gemmological Association of Great Britain, before being incorporated in 1847. The organisation is now an educational charity and accredited awarding body with its courses taught worldwide. The first US graduate of Gem-A' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsavorite
Tsavorite or tsavolite is a variety of the garnet group species grossular, a calcium-aluminium garnet with the formula Ca3 Al2 Si3 O12. Trace amounts of vanadium or chromium provide the green color. In 1967, British gem prospector and geologist Campbell R. Bridges discovered a deposit of green grossular in the mountains of Simanjiro District of Manyara Region of north-east Tanzania in a place called Lemshuko, away from Komolo, the first village. The specimens he found were of very intense color and of high transparency. The find interested the gem trade, and attempts were made to export the stones, but the Tanzanian government did not provide permits. Believing that the deposit was a part of a larger geological structure extending possibly into Kenya, Bridges began prospecting in that nation. He was successful a second time in 1971, when he found the mineral variety there, and was granted a permit to mine the deposit. The gemstone was known only to mineral specialists unti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garnet
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. Garnet minerals, while sharing similar physical and crystallographic properties, exhibit a wide range of chemical compositions, defining distinct species. These species fall into two primary solid solution series: the pyralspite series (pyrope, almandine, spessartine), with the general formula [Mg,Fe,Mn]3Al2(SiO4)3; and the ugrandite series (uvarovite, grossular, andradite), with the general formula Ca3[Cr,Al,Fe]2(SiO4)3. Notable varieties of grossular include Grossular#Hessonite, hessonite and tsavorite. Etymology The word ''garnet'' comes from the 14th-century Middle English word ''gernet'', meaning 'dark red'. It is borrowed from Old French ''grenate'' from Latin language, Latin ''granatus,'' from ''granum'' ('grain, seed'). This is possibly a reference to ''mela granatum'' or even ''pomum granatum'' ('pomegranate', ''Punica granatum''), a plant whose fruits conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translucency
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions are much larger than the wavelengths of the photons in question), the photons can be said to follow Snell's law. Translucency (also called translucence or translucidity) is the physical property of allowing light to pass through the material (with or without scattering of light). It allows light to pass through but the light does not necessarily follow Snell's law on the macroscopic scale; the photons may be scattered at either of the two interfaces, or internally, where there is a change in the index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale Of Mineral Hardness
The Mohs scale ( ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs, in his book (English: Attempt at an elementary method for the natural-historical determination and recognition of fossils); it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial setting. Reference minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translucent
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale (one in which the dimensions are much larger than the wavelengths of the photons in question), the photons can be said to follow Snell's law. Translucency (also called translucence or translucidity) is the physical property of allowing light to pass through the material (with or without scattering of light). It allows light to pass through but the light does not necessarily follow Snell's law on the macroscopic scale; the photons may be scattered at either of the two interfaces, or internally, where there is a change in the index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sapphire
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name ''sapphire'' is derived from the Latin word ', itself from the Greek language, Greek word (), which referred to lapis lazuli. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called ruby, rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on the locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewellery, jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large boule (crystal), crystal boules. Because of the remarkable hardness of sapphires 9 on the Mohs scale of miner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruby
Ruby is a pinkish-red-to-blood-red-colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires; given that the rest of the corundum species are called as such, rubies are sometimes referred to as "red sapphires". Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. The word ''ruby'' comes from ''ruber'', Latin for red. The color of a ruby is due to the presence of chromium. Some gemstones that are popularly or historically called rubies, such as the Black Prince's Ruby in the British Imperial State Crown, are actually spinels. These were once known as "Balas rubies". The quality of a ruby is determined by its color, cut, and clarity, which, along with carat weight, affect its value. The brightest and most valuable shade of red, called blood-red or pigeon blood, commands a lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emerald
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.Hurlbut, Cornelius S. Jr., and Kammerling, Robert C. (1991). ''Gemology'', John Wiley & Sons, New York, p. 203, . Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds have many inclusions, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate. Etymology The word "emerald" is derived (via and ), from Vulgar Latin: ''esmaralda/esmaraldus'', a variant of Latin ''smaragdus'', which was via (smáragdos; "green gem"). The Greek word may have a Semitic, Sanskrit or Persian origin. According to ''Webster's Dictionary'' the term emerald was first used in the 14th century. Properties determining value Emeralds, like all colored gemstones, are graded using four basic parameters known as "the four ''C''s": ''color'', ''clarity,'' ''cut'' and ''carat weight''. Normally, in grading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greece
Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically related city-states and communities. Prior to the Roman period, most of these regions were officially unified only once under the Kingdom of Macedon from 338 to 323 BC. In Western history, the era of classical antiquity was immediately followed by the Early Middle Ages and the Byzantine period. Three centuries after the decline of Mycenaean Greece during the Bronze Age collapse, Greek urban poleis began to form in the 8th century BC, ushering in the Archaic period and the colonization of the Mediterranean Basin. This was followed by the age of Classical Greece, from the Greco-Persian Wars to the death of Alexander the Great in 323 BC, and which included the Golden Age of Athens and the Peloponnesian War. The u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamantaire
A diamantaire (''French origin'') could be a gem-quality diamond manufacturer or producer, master diamond cutter, and or a graduate gemologist specializing in diamonds. Such individuals demonstrate considerable expertise in different types of gemstones, particularly when it comes to increasing the value and quality of a rough or raw diamond. They are highly skilled craftsmen or artisans who are responsible for cutting, polishing and transforming a rough diamond into a finished gemstone ready for setting. Members of diamond dealing families who have established themselves in the upper echelons of the world diamond industry hierarchy are also often referred to as ''diamantaires'' as well. See also *Diamond cutting Diamond cutting is the practice of shaping a Diamond (gemstone), diamond from a rough stone into a faceted gem. Cutting diamonds requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty. The first guild ... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
