MINERALS AND ROCKS - PROPERTIES AND USES

MINERALS AND ROCKS THEIR PROPERTIES AND USES ROCKS ANDESITE: An igneous, volcanic rock, brown, greenish to dark gray that forms when magma of dioritic composition is erupted as lava flows or injected into fractures of volcanic vents and cones in the form of dikes and domes. The darker colored andesite can be mistaken for basalt in many cases. ................
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