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These gems have slight impurities that act as chromophores and give the stone its color. An example is the gem family beryl which has the base chemical formula of Be 3 Al 2 (SiO 3 ) 6 . Pure beryl will appear colorless but this rarely occurs and the presence of trace elements change its color.
Sapphire is a precious gemstone, a variety of the ... Sapphires from different geographic locations may have different appearances or chemical-impurity concentrations ...
Corundum is a crystalline form of aluminium oxide (Al 2 O 3) typically containing traces of iron, titanium, vanadium, and chromium. [3] [4] It is a rock-forming mineral.It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. [7]
Diamonds are separated into five types: Type IaA, Type IaB, Type Ib, 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. [1] Different diamond types react in different ways to diamond enhancement techniques.
Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al 2 Si O 4 (F, OH) 2.It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden brown to yellow-orange. [7]
Titanite crystal model. Titanite, or sphene (from Ancient Greek σφηνώ (sphēnṓ) 'wedge'), [5] is a calcium titanium nesosilicate mineral, Ca Ti Si O 5.Trace impurities of iron and aluminium are typically present.
Fluorite is allochromatic, meaning that it can be tinted with elemental impurities. Fluorite comes in a wide range of colors and has consequently been dubbed "the most colorful mineral in the world". Every color of the rainbow in various shades is represented by fluorite samples, along with white, black, and clear crystals.
Fluxes are also used in foundries for removing impurities from molten nonferrous metals such as aluminium, or for adding desirable trace elements such as titanium. As reducing agents, fluxes facilitate soldering, brazing, and welding by removing oxidation from the metals to be joined. In some applications molten flux also serves as a heat ...