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Pink Diamond
Pink diamond is a type of diamond that has pink color. The source of their pink color is greatly debated in the gemological world but it is most commonly attributed to plastic deformation that these diamonds undergo during their formation. Pink diamonds belong to a subcategory of diamonds called color diamonds, the generic name for all diamonds that exhibit any sort of color. Pink diamonds range from flawless to included, as do white diamonds. Origin of the pink color Numerous theories have been posited as to how the pink is formed in pink diamonds. The prevailing theory is that the pink is caused when the diamond is subjected to shear pressure during its formation. A similar theory is being tested on pink diamonds that originated in the Argyle Mine in Kimberley, Western Australia. This theory posits that a seismic shock propelled colorless diamonds to the surface and altered their molecular structure, causing them to appear pink. Properties determining value The same four bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Element Minerals
Native element minerals are those chemical element, elements that occur in nature in Free element, uncombined form with a distinct mineral structure. The elemental class includes native metal, metals, intermetallic compounds, alloys, metalloids, and nonmetals. The Nickel–Strunz classification system also includes the naturally occurring phosphides, silicides, nitrides, carbides, and arsenides. Elements The following elements occur as native element minerals or alloys: Nickel–Strunz Classification -01- Native elements This list uses the Strunz classification, Classification of Nickel–Strunz (mindat.org, 10 ed, pending publication). ;Abbreviations: * "*" – discredited (IMA/CNMNC status). * "?" – questionable/doubtful (IMA/CNMNC status). * "REE" – Rare-earth element (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) * "PGE" – Platinum group, Platinum-group element (Ru, Rh, Pd, Os, Ir, Pt) * 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carat (mass)
The carat (ct) is a unit of mass equal to or 0.00643 troy oz, and is used for measuring gemstones and pearls. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in many countries around the world. The carat is divisible into 100 ''points'' of 2 mg. Other subdivisions, and slightly different mass values, have been used in the past in different locations. In terms of diamonds, a paragon is a flawless stone of at least 100 carats (20 g). The ANSI X.12 EDI standard abbreviation for the carat is CD. Etymology First attested in English in the mid-15th century, the word ''carat'' comes from Italian ''carato'', which comes from Arabic '' qīrāṭ '' قيراط , in turn borrowed from Greek ''kerátion'' κεράτιον 'carob seed', a diminutive of ''keras'' 'horn'. It was a unit of weight, equal to 1/1728 (1/12) of a pound (see Mina (unit)). History Caro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guntur
Guntur () is a city and the administrative headquarters of Guntur district in the States and union territories of India, Indian state of Andhra Pradesh. Guntur is spread across 168.49 km square and is the third-largest city in the state. It is situated to the west of the Bay of Bengal, on the Eastern Coastal Plains. The city is the heartland of the state, located in the centre of Andhra Pradesh and making it a central part connecting different regions. It serves as a major hub for exports chilli, cotton and tobacco and has the largest chili market yard in Asia. It is a major transportation, education and commercial hub for the state. Guntur city is a municipal corporation and also the headquarters of Guntur East mandal, Guntur East and Guntur West mandals in Guntur revenue division. The city region is a major part of Amaravati Metropolitan Region Development Authority, Amaravati Metropolitan Region. 2011 Census of India, census of India the city is the List of cities in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kollur Mine
Kollur Mine was a series of gravel-clay pits on the south bank of the Krishna River in the Golconda Sultanate of India. It currently falls within the state of Andhra Pradesh. It is thought to have produced many large diamonds, known as Golconda diamonds, several of which are or have been a part of crown jewels. The mine was established in the 16th century and operated until the 19th century. History Kollur Mine operated between the 16th and mid-19th centuries, and was one of the largest and most productive diamond mines on the Indian subcontinent. At the height of production, around 30,000 – 60,000 people worked there, including men, women, and children of all ages. Kollur itself had a population of around 100,000. Golconda mines were owned by the king, but operation was leased to diamond merchants, either foreigners or Indians of the goldsmith caste. As well as rent, the king also received 2% from sales and he was entitled to keep all diamonds weighing over 10 carat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives; its Andaman and Nicobar Islands share a maritime border with Thailand, Myanmar, and Indonesia. Modern humans arrived on the Indian subcontinent from Africa no later than 55,000 years ago., "Y-Chromosome and Mt-DNA data support the colonization of South Asia by modern humans originating in Africa. ... Coalescence dates for most non-European populations average to between 73–55 ka.", "Modern human beings—''Homo sapiens''—originated in Africa. Then, interm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Vapor Deposition
Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber. Microfabrication processes widely use CVD to deposit materials in various forms, including: monocrystalline, polycrystalline, amorphous, and epitaxial. These materials include: silicon (dioxide, carbide, nitride, oxynitride), carbon (fiber, nanofibers, nanotubes, diamond and graphene), fluorocarbons, filaments, tungsten, titanium nitride and various high-κ dielectrics. The term ''chemical vapour deposition'' was coined 1960 by ''John M. Blocher, Jr.'' who intended to differentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loupe
A loupe ( ) is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached handle, and its focusing lens(es) are contained in an opaque cylinder or cone. On some loupes this cylinder folds into an enclosing housing that protects the lenses when not in use. Optics Three basic types of loupes exist: * Simple lenses, generally used for low-magnification designs because of high optical aberration. * Compound lenses, generally used for higher magnifications to control optical aberration. * Prismatic, multiple lenses with prisms. Uses Loupes are used in many professions where magnification enables precision work to be done with greater efficiency and ease. Examples include surgery, dentistry, ophthalmology, the jewelry trade, gemology, and watchmaking. Loupes are also sometimes used in photography and printing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Type
Diamond type is a method of scientifically classifying diamonds by the level and type of their chemical impurities. Diamonds are separated into five types: Type Ia, Type Ib, Type 1aB, Type IIa, and Type IIb. The impurities measured are at the atomic level within the crystal lattice of carbon atoms and so, unlike inclusions, require an infrared spectrometer to detect. Different diamond types react in different ways to diamond enhancement techniques. Different types can coexist within a single stone; natural diamonds are often mixes of Type Ia and Ib, which can be determined by their infrared absorption spectrum. Types of Diamond Type I Type I diamonds, the most common class, contain nitrogen atoms as their main impurity, commonly at a concentration of 0.1%. Type I diamonds absorb in both the infrared and ultraviolet region, from 320 nm. They also have a characteristic fluorescence and visible absorption spectrum (see Optical properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightness (color)
Lightness is a visual perception of the luminance (L) of an object. It is often judged relative to a similarly lit object. In colorimetry and color appearance models, lightness is a prediction of how an illuminated color will appear to a standard observer. While luminance is a linear measurement of light, lightness is a linear prediction of the human perception of that light. This is because human vision's lightness perception is non-linear relative to light. Doubling the quantity of light does not result in a doubling in perceived lightness, only a modest increase. The symbol for perceptual lightness is usually either J as used in CIECAM02 or L^* as used in CIELAB and CIELUV. L^* ("Lstar") is not to be confused with L as used for luminance. In some color ordering systems such as Munsell, Lightness is referenced as value. Chiaroscuro and Tenebrism both take advantage of dramatic contrasts of value to heighten drama in art. Artists may also employ shading, subtle manipulatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturation (color Theory)
Colorfulness, chroma and saturation are attributes of perceived color relating to chromatic intensity. As defined formally by the International Commission on Illumination (CIE) they respectively describe three different aspects of chromatic intensity, but the terms are often used loosely and interchangeably in contexts where these aspects are not clearly distinguished. The precise meanings of the terms vary by what other functions they are dependent on. * Colorfulness is the "attribute of a visual perception according to which the perceived color of an area appears to be more or less chromatic"., page 87. The colorfulness evoked by an object depends not only on its spectral reflectance but also on the strength of the illumination, and increases with the latter unless the brightness is very high ( Hunt effect). * Chroma is the "colorfulness of an area judged as a proportion of the brightness of a similarly illuminated area that appears white or highly transmitting". As a resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Color
A chemically pure and structurally perfect diamond is perfectly transparent with no hue, or ''color''. However, in reality almost no gem-sized natural diamonds are absolutely perfect. The color of a diamond may be affected by chemical impurities and/or structural defects in the crystal lattice. Depending on the hue and intensity of a diamond's coloration, a diamond's color can either detract from or enhance its value. For example, most white diamonds are discounted in price when more yellow hue is detectable, while intense pink diamonds or blue diamonds (such as the Hope Diamond) can be dramatically more valuable. Of all colored diamonds, red diamonds are the rarest. The Aurora Pyramid of Hope displays a spectacular array of naturally colored diamonds, including red diamonds. History of color grading Color grading of diamonds was performed as a step of sorting rough diamonds for sale by the London Diamond Syndicate. As the diamond trade developed, early diamond grades were in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iranian Crown Jewels
The Iranian National Jewels ( fa, جواهرات ملی ایران, ''Javāherāt-e Melli-ye Irān''), originally the Iranian Crown Jewels ( fa, جواهرات سلطنتی ایران, ''Javāherāt-e Saltanati-ye Irān''), include elaborate crown (headgear), crowns, thirty tiaras, and numerous aigrettes, a dozen bejeweled swords and shields, a number of unset precious gems, numerous plates and other dining services cast in precious metals and encrusted with gems, and several other more unusual items (such as a large golden globe with the oceans made of emeralds) collected or worn by the List of monarchs of Persia, Persian monarchs from the 16th century (Safavid dynasty, Safavid Persia) and on. The collection is housed at the Treasury of National Jewels, situated inside the Central Bank of Iran on Tehran's Ferdowsi Avenue. Safavid and Afsharid conquests The majority of the items now in the collection were acquired by the Safavid dynasty, which ruled Iran from 1502 to 1736 AD. Af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
