COMM 201 Lecture Notes - Lecture 3: Feldspar, Chemical Formula, Crystal Habit
30 Mar 2018
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Document Summary
Minerals control everything, without a solid understanding of minerals it is impossible to understand earth processes. 4000 different minerals rocks of the accessible earth are >95% made up by ~ two handfuls of minerals. mineral: a solid with a highly ordered atomic arrangement and a definite homogenous chemical composition. Highly ordered atomic arrangement: internal structural framework of atoms/ions arranged in a regular repeating geometric pattern. crystalline (compared to amorphous) Definite but not necessarily fixed composition: varies within limits. Implies the composition of a mineral can be expressed by a specific chemical formula. Most minerals however are solid solutions: composition can vary in certain limits. , other minerals show immiscibility at certain conditions. Sometimes we have a solid solution between two types but not the third one feldspar diagram and its temperature dependence in the k-feldspar. There are many different ways to describe types of minerals.
