Emeralding base

Espig A process for making synthetic emeralds by the flux reaction technique. Beryllia and alumina are dissolved in molten lithium molybdate, and silica is floated on the melt. The emerald crystals form at the base of the melt, but because they tend to float and mix with the silica, a platinum screen is suspended in the middle of the melt. Invented by H. Espig. 

The free base is obtained by rubbing the moist salt (5-10 g.) under sodium carbonate solution in a separating funnel and shaking with ether until the whole is dissolved. The beautiful emerald green solution is first concentrated on the water bath and then the solvent is allowed to evaporate from a flat dish exposed to the air. Large green plates of nitrosodimethylaniline remain. They melt at 80° and can be recrystallised from petrol ether (boiling point 60°-80°). 

Because chemical and structural properties of natural and artificial gems are very similar in this case, the possibilities of Raman and LIBS methods are rather limited. It was found that another laser-based techniques could be very effective for rapid spectroscopic discrimination between natural and synthetic emeralds, rubies, and alexandrite (Armstrong et al. 2000a,b). The first one is DRIFTS (Diffuse Reflectance Fourier Transformed Infra-Red Spectroscopy)... 

The blue-green adduct was heated in vacuum at 45° for 20 hours to yield emerald-green crystals of [Rh(OCOCH3)2]2. A check on the removal of methanol can be made periodically by taking an infrared spectrum. Overall yield is 3.2 g. (76% based on RhCl3-3H20). Anal. Calcd. C, 21.74 H, 2.74. Found C, 21.79 H, 2.99. 

In addition to time-of-flight techniques, other methods based on current measurements have been described. Space-charge-limited current techniques have been reported by Lampert and Mark (1970), Mort and Emerald (1974), Nespurek and Silinsh (1976), Sworakowski and Nespurek (1979), Silinsh... 

A gem closely related to ruby and emerald is alexandrite, named after Alexander II of Russia. This gem is based on the mineral chrysoberyl, a beryllium aluminate with the empirical formula BeO AI2O3 in which approximately 1% of the Al3+ ions are replaced by Cr3+ ions. In the chrysoberyl environment Cr3+ absorbs strongly in the yellow region of the spectrum. Alexandrite has the interesting property of changing colors depend-... 

In solid-state laser materials, such as ruby (chromium doped alumina, AljOjiCr " ) (1) and emerald (chromium doped beryl, Be,Al,(Si03)5 Cr ) (2), transitions between multiplets of impurity states are utilized. These states mainly consist of 3d orbitals of the impurity chromium ions. For the analysis of these multiplet structures, the semi-empirical ligand-field theory (LFT) has been frequently used (3). However, this theory can be applied only to the high symmetry systems such as O, (or T ). Therefore, the effect of low symmetry is always ignored in the analysis based on the LFT, although most of the practical solid-state laser materials actually possess more or less distorted local structures. For example, in ruby and emerald, the impurity chromium ions are substituted for the aluminum ions in the host crystals and the site symmetry of the aluminum ions are C, in alumina and D, in beryl. Therefore, it is important to clarify the effect of low symmetry on the multiplet structure, in order to understand the electronic structure of ruby and emerald. 

Thirdly, according to what is written this medicine changes all stones into precious ones, as in jasper. White and Red Coral, Emerald, Chrysolite, Sapphires, fnrther Crystals into Garnets, Rnbies and Topazes, which are much more powerful than the natnral ones. It softens and fuses all base and precious stones. 

Emerald green, cryst powder. Poisonous Stable to air, light. Practically insol in water dec on prolonged heating in water. Unstable in acids, bases, and toward H2S. LDSU orally in female rats 100 mg/kg, T. B. Gaines, Toxicol... 

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