Beryl color

Maximum working-solution capacity, 14 46 Maximum work obtainable, for a change of state involving mixtures, 24 690-692 Maxixe beryl, color, 7 337 Maxon sutures, 24 222 Maxwell-Boltzmann distribution, silicon-based semiconductors and, 22 235, 236, 238... 

In UK and Europe only beryl colored by chromium may be described as emeraid. 

Solntsev V, Bukin G (1997) The nature of beryl color from rare metal pegmatite. Russian Geol Geophys 38(10) 1661-1668... 

Scandium is apparently much more abundant (the 23rd most) in the sun and certain stars than on earth (the 50th most abundant). It is widely distributed on earth, occurring in very minute quantities in over 800 mineral species. The blue color of beryl (aquamarine variety) is said to be due to scandium. It occurs as a principal component in the rare mineral thortveihte, found in Scandinavia and Malagasy. It is also found in the residues remaining after the extrachon of tungsten from Zinnwald wolframite, and in wiikite and bazzite. 

Several gemstone species occur in various colors, depending on the presence of impurities or irradiation-induced color centers. Examples are the beryl, comndum, and quart2 families. Quart2 has poor optical properties (RI = 1.55, DISP = 0.013), but becomes of gemological interest when it exhibits attractive colors. Any material can have its color modified by the addition of various impurities synthetic mby, sapphires, and spinel are produced commercially in over 100 colors (2). Synthetic cubic 2irconia has been made in essentially all colors of the spectmm (11), but only the colorless diamond imitation is produced commercially in any quantity. 

Beryl. Beryl [1302-52-9] Be Al Si O g, is called aquamarine [1327-51 -1] when pale green or blue from inclusion of Fe emerald [12415-33-7] when dark green from Cr or at times V, and morganite or red beryl when pink or red, respectively, from Mn. Only the synthetic emerald is in commercial production, although the other colors can also be grown. Both the flux and hydrothermal techniques are used to grow this luxury synthetic. 

A thin layer of dark green beryl had been grown by a hydrothermal technique over the surface of a pale beryl to imitate emerald. It has been suggested that such stones should be called synthetic emerald-beryl doublets (16). The abiHty to grow thin, but not thick, single-crystal diamond on the surface of natural diamond (17) leads to the possibiHty of growing such a thin film colored blue with boron this has been done experimentally (18). 

FIGURE 14.20 An emerald is a crystal of beryl with some Cr + ions, which are responsible for the green color. 

Colored beryl gems, for example, aquamarine, are highly sought-after... 

A colorless mineral known as corundum (composed of aluminum oxide) is colorless. A red variety of corundum known as ruby, a precious stone, owes its color to impurities of chromium within the crystal structure of corundum. Blue and violet varieties of corundum are classified as sapphires, the blue being the result of iron and titanium impurities, and the violet of vanadium impurities within the corundum crystal structure. Another colorless mineral is beryl (composed of beryllium aluminum silicate) but blue aquamarine, green emerald, and pink morganite, are precious varieties of beryl including different impurities aquamarine includes iron, emerald chromium and vanadium, and morganite manganese. 

Mineral gemstones that have the same basic chemical composition, that is, are composed of the same major elements and differ only in color, are considered as variations of the same mineral species. As gemstones, however, minerals that have the same composition and crystalline structure but exhibit different colors are classified as different gemstones. Beryl, for example, a mineral (composed of beryllium aluminum silicate), includes a pink variety, known by the gemstone name of morganite, and also a well-known green variety, emerald. Table 18 lists and classifies, by composition and color, gemstones that have been appreciated since antiquity. 

Bernoulli principle, 11 656-657 Berry pseudo-rotation, 16 62 Bertrandite, 3 638, 640-641 Bertrand lens, 16 470-471 Beryl, 3 638, 640 color, 7 329... 

Now as I beheld the living creatures, behold one wheel upon the earth by the living creatures, with his four faces. The appearance of the wheels and their work was like unto the color of a beryl and they four had one likeness and their appearance and their work was as it were a wheel in the middle of a wheel. When they went, they went... 

Gem quality beryls are aquamarine (blue), emerald (green), and golden beryl. Likewise, amethyst b a violet-colored silica, and sapphire (blue) and ruby (red) are alumina. Yet pure beryl (Be,AI>Si lO ). alica (SiO ). and alumina (AI O>) are colorless. Explain... 

CHRYSOBERYL. The mineral chrysoberyl. an aluminaie of hery Ilium corresponds to the formula BeALO. , crystallizes in the orthorhombic system with both contact and penetration twins common, often repeated resulting in ro.setted structures. Hardness. 8.5 specific gravity. 3.75 luster vitreous color various shades of green sometimes yellow. A variety which is red by transmitted light is known as alexandrite. Streak colorless transparent to translucent, occasionally opalescent. Chrysoberyl also is known as cymopbane and golden beryl. 

EMERALD. This beautiful green variety of the mineral beryl has been known since ancient times and always prized as a gem. both because of its color ami relative rarity. It is frequently cloudy or flawed, hence the expression rare as an emerald without a flaw." The original source of emeralds seems to be the so-called Cleopatra s mines in Egypt, where in a range of low mountains about 15 miles (24 kilometers) from the Red Sea. they arc found in schists. The quality uf these emeralds is not high, but there is much evidence of considerable workings in a former period. See also Beryl. 

In verse 16 we have a most wonderful description of the circulations taking place in the matter of the Art, which D Espagnet refers to as so many "whorls." Ezekiel terms them "wheels" - "a wheel in the middle of a wheel." The key, as usual, is the color, being that of beryl, a crystal of a sea-green color, or of a rose-red. Both these colors appear in the Stone at this stage. 

Emerald is a variety of beryl, a beryllium silicate, with a hardness of 7.5 to 8. It has a beautiful deep green color, and it is one of the most expensive gems, sometimes outranking diamond in value. The green color results from small amounts of chromic oxide (Cr203). The oldest emerald mines were in Egypt near the Red Sea, but the best emerald mines today are in Colombia. There are others in Brazil, Pakistan, and Africa synthetic emeralds of excellent quality have also been manufactured. 

Aquamarine, like emerald, is a transparent variety of beryl, or beryllium silicate. Its light blue to blue-green color results from small amounts of iron in the crystal. Like most beryl stones, it measures 7.5 to 8 on the Mohs hardness scale. Most aquamarine gemstones come from Brazil. 

Beryl Aquamarine, emerald BesA SiOs) All colors, 2.70-2.82 1.580-1.575 7.5-8 Poor cleavage perpendi-... 

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