Which mineral is the second-most abundant mineral in the continental crust and the only common mineral made completely of silicon and oxygen?
A. Feldspar
B. Calcite
C. Silicon dixiode
D. Mica
查看答案
Smoky quartz is the quartz contains trace amounts of:
Al
B. Fe
Ca
D. Mg
The silicate minerals are the most common type of minerals. What's the percentages do they account for of Earth's crust?
A. Less than 50%
B. About 50%
C. More than 90%
D. Less than 10%
The crystals of magnetite are:
A. Cubes
B. Octahedrons
C. Dodecahedrons
The crystals of fluorite are:—crystals are cubes
A. Cubes
B. Octahedrons
C. Dodecahedrons
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