Abundance 1041 Ruby

Chromium, 122 ppm of the earth s crustal rocks, is comparable in abundance with vanadium (136 ppm) and chlorine (126 ppm), but molybdenum and tungsten (both 1.2 ppm) are much rarer (cf. Ho 1.4 ppm, Tb 1.2 ppm), and the concentration in their ores is low. The only ore of chromium of any commercial importance is chromite, FeCr204, which is produced principally in southern Africa (where 96% of the known reserves are located), the former Soviet Union and the Philippines. Other less plentiful sources are crocoite, PbCr04, and chrome ochre, Cr203, while the gemstones emerald and ruby owe their colours to traces of chromium (pp. 107, 242). 

Mg, Mn and Ca in garnets with a Jarrell-Ash laser microprobe, using ruby and neodymium lasers have shown that reliable data on the abundance of the different elements can be obtained in a very short time. 

Aluminum is the most abundant metal and the third most abundant element, after oxygen and silicon, in the earth s crust. It is widely distributed and constitutes approximately 8 percent of the earth s surface layer. However, aluminum is a very reactive element and is never found as the free metal in nature. It is found combined with other elements, most commonly with oxygen, silicon, and fluorine. These chemical compounds are commonly found in soil, minerals (e.g., sapphires, rubies, turquoise), rocks (especially igneous rocks), and clays. These are the natural... 

Lee KH, Ruby EG. Effect of squid host on the abundance and distribution of symbiotic Vibrio fischeri in nature. Appl Environ Microbiol 1994 60 1565-71. 

Vanadinite, 3 Pb3(V04)2 PbCl2 or (PbCl)Pb4(V04)3, is the mineral from which Del Rio first obtained vanadium material. It contains from 8 to 21 per cent V20 6, varies in color from deep ruby red to a straw yellow, and is found in Mexico, Urals, Sweden, Argentina, and abundantly in the mining regions of Arizona and New Mexico. 

Stn. Alumina Pure Clay.—Tins earth is veiy abundant in nature. It occurs crystallised as the sapphire and ruby in a crystalline, but more massive form, as corundum or emery and as the chief ingredient of all clays, and of most slaty rocks, from which, indeed, clays are derived. Pipe-clay is the purest clay, but is not pure alumina, although approaching to it. ... 

Some very interesting double resonance experiments were carried out on ruby (155-161). A single crystal of ruby at liquid helium temperature was placed in a constant magnetic field and simultaneously subjected to the microwave ESR frequency of the chromium spins and the NMR radiofrequency of either the AP or the Cr (9.54 % abundant) nucleus. The results were as follows. 

Aluminum is one of the most abundant elements on Earth and, in its oxidized form, is a constituent of most common minerals. Pure aluminum oxide is relatively rare, but may be found in the form of single crystal, when it is used as a gemstone in its colorless (sapphire) or red (ruby, due to the admixing of chromium) modifications. 

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