EARTHSC 1G03 Chapter Notes - Chapter 2: Mohs Scale Of Mineral Hardness, Crystal Habit, Biomineralization
5 Apr 2017
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Document Summary
Formed by geologic processes, with a definable chemical composition and an internal structure characterized by an orderly arrangement of atoms, ions or molecules in a crystalline lattice. Biogenic minerals such as those in clam shells are produced by organisms through a process called biomineralization. In the crystalline lattice of minerals, atoms occur in a specific pattern- one of nature"s finest example"s of ordering. Minerals can form by solidification of a melt, precipitation from a water solution, diffusion through a solid, metabolism of organisms, or precipitation from a gas. Mineralogists have identified about 4000 different types of minerals. Each has a name and distinctive physical properties. Colour, streak, luster, hardness, specific gravity, crystal habit, cleavage, magnetism, and reactivity with acid. Colour is how the mineral interacts with light. Least reliable, same elements can come in different colours, and many different elements can be the same colour. Streak is the colour of the powder produced when you crush the mineral.
