Chemistry

mg/g, ppm, dispersed, trace elements

simple anionic and cationic substitution, coupled substitutions

interstitial solid solution, omission solid solution

exsolution or unmixing

perthite, microperthite, cryptoperthite, antiperthite

miscibility gap

diffusion

solid solution

Suppose a certain bulk composition exists in the upper crust and in the middle mantle. In general terms, what differences might I expect between the minerals in these two locations?

Explain the various ways in which minerals can vary in chemistry, i.e. what are the mechanisms of elemental variation?

Explain the nature of exsolution, and sketch a diagram of a miscibility gap and explain what happens as a crystal hits the miscibility gap upon cooling.

What are the eight most abundant elements in the crust by weight?

What are the various ways that the chemistry of a particular mineral can vary? Describe every method you can think of, briefly explain each, and discuss the degree to which each method can produce chemical change.

Explain exsolution and give 2 examples in nature.

Sketch a miscibility gap (T-X) diagram and explain what happens as crystals grow from a melt, then cool, for various parts of the diagram.