Volcanism
Volcanic eruptions are the clear and dramatic expression of dynamic processes going on in planet Earth. The author, one of the most profound specialists in the field of volcanology, explains in a concise and easy way how to understand manner the basics and most recent findings in the field of volcanology.
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Mineral A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal morphology and physical properties such as density and hardness. Minerals are the fundamental units from which most rocks are made. |
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Common minerals in volcanic rocks include quartz [SiO 2 ], anorthite feldspar [CaAl 2 Si 2 O 8 ] olivine [(Fe,Mg) 2 SiO 4 ], magnetite [Fe 3 O 4 ], biotite [K(Mg,Fe) 3 AlSi 3 O 10 (OH) 2 and pyroxene [Ca,Fe,Mg) 2 Si 2 O 6 ]
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Obsidian (volcanic glass) is not a mineral because glass has no orderly internal structure.
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Amber is not a mineral because it is formed by organic processes, and its chemical composition can vary.
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Rocks, such as granite or sandstone, are mixtures of minerals. Their compositions can vary widely and cannot be approximated by a mineral formula.
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The Moh's Hardness Scale is used to calibrate the hardness of minerals. The list, in order from soft to hard, is as follows:
Moh's Hardness scale
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Ring of Fire - IMAX
The Closest You'll Ever Get to a Volcano Originally filmed in IMAX Ring of Fire takes you heart stopping close to the great circle of volcanoes and seismic activity that rings the Pacific Ocean. This film has been seen by millions of people. The story of these immense volcanic forces and the half a billion people that coexist with them every day around the fiery boundary of the Pacific Rim
