Yellow beryl

Heliodor is the golden yellow gem variety of beryl due to the isomorphous substitution of aluminum by ferric cations. It is also known as yellow beryl if the golden tint lacking. Good colored material is relatively rare. As other gem varieties of beryl it is found in granitic pegmatites in Brazil in the Ural Mountains (Russia), and Namibia. 

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. 

Figure 1 Structure of beryl, Al2Be3Si60i8 (A1 = yellow, Be = orange. Si = blue, O = red)...

Match 18.13 Color Red Group Quartz Beryl yellow... 

Description. Morganite is a pink to peach-colored gem variety of beryl, named after J.P. Morgan, the famous financier and banker. The color is due to the doping by manganous cations. A deep red gem variety of beryl occurring at the Ruby Violet Mine in the Wah Wah mountains Utah, is not called morganite, but red beryl. Heat treatment of some specimens renders them colorless, in others heating may be used to drive off a yellow overtone produced by a yellow color center to yield a nice pink. 

Two gemstones, beryl and emerald, have been known since ancient times, the former yellow like gold the latter a lovely green. In the Old Testament, predous stones are mentioned in different contexts, as for example in the instructions for the High Priest s breastplate ... 

An example of a cyclosiHcate is beryl BejAljSi Ojg (Figure M58). It usually occurs in green, bluish-green, yellow or pink hexagonal prisms. Transparent and colored gem varieties include emerald, aquamarine, heliodor and golden beryl. In the tourmaline... 

This test is affected by large amounts of ammonium salts they should be removed beforehand. Aluminum, in not too great excess, lead, zinc, and antimony salts do not interfere. Solutions of copper and nickel salts can be decolorized by adding potassium cyanide, whereas cobalt salts form the Light yellow soluble potassium cobalticyanide K3[Co(CN) ], which does not interfere with the recognition of the blue of the quinalizarin compound. Iron salts may be masked by means of tartrates. However, tartrates interfere if aluminum is present because a red color is formed in the caustic alkaline solution of quinalizarin. If both iron and aluminum are present, the test solution should be treated with 5 ml of 1 iV NaOH, cooled, diluted to 15 ml, and then filtered if necessary. The dear solution contains any beryllium as beryllate and can be tested as described below. 

A good procedure for the detection of beryllium in rocks and minerals is based on the fact that alkali beryllate produces a water-soluble yellow-green fluorescent compound with morin. ... 

Not only does the observed color depend rm the nature of the transition metal impurity, but on the oxidation state of the dopant. For instance, the color of a beryl-based crystal changes from blue to yellow, upon doping with Fe + and Fe + (Aquamarine and HeUodor), respectively. For Mn and Mn + impurities... 

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