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Diamond Color
A chemically pure and structurally perfect diamond (gemstone), 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 colors of chemicals, chemical impurities and/or structural defects in the Crystal structure#Lattice systems, 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 colorless (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 Londo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Hope Diamond - SIA
''The'' is a grammatical Article (grammar), article in English language, English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the Most common words in English, most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Properties Of Diamond
Diamond is the allotrope of carbon in which the carbon atoms are arranged in the specific type of cubic lattice called diamond cubic. It is a crystal that is transparent to opaque and which is generally isotropic (no or very weak birefringence). Diamond is the hardest naturally occurring material known. Yet, due to important structural brittleness, bulk diamond's toughness is only fair to good. The precise tensile strength of bulk diamond is little known; however, compressive strength up to has been observed, and it could be as high as in the form of micro/nanometer-sized wires or needles (~ in diameter, micrometers long), with a corresponding maximum tensile elastic strain in excess of 9%. The anisotropy of diamond hardness is carefully considered during diamond cutting. Diamond has a high refractive index (2.417) and moderate dispersion (0.044) properties that give cut diamonds their brilliance. Scientists classify diamonds into four main types according to the nature of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Clarity
Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called ''inclusions'', and surface defects, called ''blemishes''. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut. Inclusions are solids, liquids, or gases that were trapped in a mineral as it formed. They may be crystals of a foreign material or even another diamond crystal, or may have produced structural imperfections, such as tiny cracks that make a diamond appear whitish or cloudy. The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under ten times magnification, which is the standard magnification for loupes used in the gem world. Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carat (mass)
The carat (ct) is a unit of mass equal to , which 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 Carob seeds have bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonado
Carbonado, commonly known as black diamond, is one of the toughest forms of natural diamond. It is an impure, high-density, micro-porous form of polycrystalline diamond consisting of diamond, graphite, and amorphous carbon, with minor crystalline precipitates filling pores and occasional reduced metal inclusions. Titanium nitride (TiN, osbornite) has been found in carbonado. It is found primarily in alluvial deposits where it is most prominent in mid-elevation equatorial regions such as Central African Republic and in Brazil, where the vast majority of carbonado diamondites have been found. Its natural colour is black or dark grey, and it is more porous than other diamonds. Unusual properties Carbonado diamonds are typically pea-sized or larger porous aggregates of many tiny black crystals. The most characteristic carbonados are mined in the Central African Republic and in Brazil, in neither place associated with kimberlite, the source of typical gem diamonds. Lead isotope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalescence
Opalescence or play of color is an optical phenomenon associated with the mineraloid gemstone opal,opalescent. 2019. In Noah Webster's 1828 American Dictionary of the English Language. Retrieved January 7, 2019, from https://1828.mshaffer.com/d/word/opalescent a hydrated silicon dioxide. This effect appears as a milky, translucent glow that changes with the angle of light, often creating a soft, pearly sheen that can display various colors or hues. Opalescence can be seen in materials like certain minerals, glass, and even fluids. Definition Each of the three notable types of opalprecious, common, and fireDouma, M., curator. 2008. Opal. In Cause of Color. Retrieved January 8, 2019, from https://webexhibits.org/causesofcolor/15F.htmldisplay different optical effects; therefore, the intended meaning varies depending on context. * The general definition of ''opalescence'' is a milky iridescence displayed by an opal, which describes the visual effect of precious opal very well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide
Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (HS−) are the conjugate acids of sulfide. Chemical properties The sulfide ion does not exist in aqueous alkaline solutions of Na2S. Instead sulfide converts to hydrosulfide: :S2− + H2O → SH− + OH− Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: :S2− + H+ → SH− :SH− + H+ → H2S Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts. :8 MgS + 8 I2 → S8 + 8 MgI2 Metal de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphite
Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on a large scale (1.3million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), and lubricants (5%), among others (17%). Graphite converts to diamond under extremely high pressure and temperature. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. Types and varieties Graphite can occur naturally or be produced synthetically. Natural graphite is obtained from naturally occurring geologic deposits and synthetic graphite is produced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclusion (mineral)
In mineralogy, an inclusion is any material trapped inside a mineral during its formation. In gemology, it is an object enclosed within a gemstone or reaching its surface from the interior. According to James Hutton's law of inclusions, fragments included in a host rock are older than the host rock itself. Mineralogy Inclusions are usually rock (geology), rocks or other minerals, less often water, gas or petroleum. Liquid and vapor create fluid inclusions. In amber, insects and plants are common inclusions. The analysis of atmospheric gas Bubble (physics), bubbles as inclusions in ice cores is an important tool in the study of climate change (general concept), climate change. A xenolith is a preexisting rock which has been picked up by a lava flow. Melt inclusions form when bits of melt become trapped inside crystals as they form in the melt. Gemology Inclusions are one of the most important factors when it comes to gem valuation. They diminish the diamond clarity, clarity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Lattice
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystal, crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal directions of Three-dimensional space (mathematics), three-dimensional space in matter. The smallest group of particles in a material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive Translation (geometry), translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of principal axes/edges, of the unit cell and angles between them are lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of a crystal are described by the concept of space groups. All possi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and Gamma ray, gamma radiation (γ) * ''particle radiation'' consisting of particles of non-zero rest energy, such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation * ''acoustics, acoustic radiation'', such as ultrasound, sound, and seismic waves, all dependent on a physical transmission medium * ''gravitational radiation'', in the form of gravitational waves, ripples in spacetime Radiation is often categorized as either ''ionizing radiation, ionizing'' or ''non-ionizing radiation, non-ionizing'' depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volt, electron volts (eV), which is enough to ionize atoms and molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-center
An F-center or color center or Farbe center (from the original German ''Farbzentrum'', where ''Farbe'' means ''color'' and ''zentrum'' means ''center'') is a type of crystallographic defect in which an anionic Vacancy defect, vacancy in a crystal lattice is occupied by one or more unpaired electrons. Electrons in such a vacancy in a crystal lattice tend to absorb light in the visible spectrum such that a material that is usually Transparency (optics), transparent becomes colored. The greater the number of F centers, the more intense the color of the compound. F centers are a type of color center. This is used to identify many compounds, especially zinc oxide (yellow). History Before the discovery of point defects it was already known that some crystals can be discolored using various methods. In 1830 T.J. Pearsall discovered that fluorspar could be discolored using violet light. Thirty years later similar results were achieved by melting crystals together with a specific metal. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
