Gemstone Chemistry

There you have it H2O, H2O2, OH, HjO . Not much difference typographically. But chemically, they re worlds apart, which exemplifies a principle called the law of definite proportions. It is not just the elements that determine the nature of a compound but the proportions, too. The ramifications of the conservation of mass and the law of definite proportions are the subjects we tackle next. 

The meeting of two personalities Is like the contact of two chemical substances if there is any reaction, both are transformed. 

We will begin our discussion of these recipes by examining two of the main principles on which they are based the conservation of mass and the law of definite proportions. The law of definite proportions defines our ingredient list and the conservation of mass tells us how big a cake weTl bake. 

The law of definite proportions tells us that our ingredients have a specific chemical formula for example, H2O is the chemical formula for water. In essence, the chemical formula consists of a list of the elements that built the substance and the numbers of atoms of each that were required. There are subtleties, however, in the arrangement of elements, just as there are subtleties in the arrangement of elements in the periodic table. More information can be gleaned from the chemical formula than just the number and type of components. 

Moreover, the order of the elements in a chemical compound is important thus, CHjCHjOH is distinguished from CH3OCH3. Both substances have two carbon nuclei, six hydrogen nuclei, and one oxygen, but the first material is ethyl alcohol, sometimes called grain alcohol, and the other is dimethyl ether, which has decidedly different properties. Compounds that have the same number and type of elements but arranged in a different order are called isomers. 

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Nassau. K. Gemstone Enhancement, 2nd Edition. Butterworths. Boston. MA. 1994, Nassau, K. The Physics and Chemistry of Color, John Wiley Sons. Inc., New York. NY, 1983,... 

The questions emphasize the need for techniques to aid the eye in examining these materials, or the need to understand the structure and chemistry of gemstones when handling them. 

Erel, E., Aubriet, F, Finqueneisel, G., Muller, J.F. (2003) Capabilities of laser ablation mass spectrometry in the differentiation of natural and artificial opal gemstones. Analytical Chemistry, 75, 6422-6429. 

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