Andesite commonly contains which minerals?

Andesite commonly contains which minerals?

• A. Granite
• B. Andesite
• C. Diorite
• D. Basalt

Answer: (B)

Andesite is an intermediate igneous rock, so its mineral makeup sits between basalt and rhyolite. The typical minerals you’d expect to see are plagioclase feldspar (often calcic plagioclase like andesine) together with ferromagnesian minerals such as hornblende (amphibole) or pyroxene. Quartz is not common in most andesites. This mineral set defines andesite and distinguishes it from other rocks with different mineral assemblages. Granite, diorite, and basalt each have their own characteristic mineralogy (granite with quartz and alkali feldspar; diorite with plagioclase and dark minerals but less quartz; basalt with pyroxene and plagioclase and little quartz). So the minerals described are most consistent with the rock type andesite.

Andesite is an intermediate igneous rock, so its mineral makeup sits between basalt and rhyolite. The typical minerals you’d expect to see are plagioclase feldspar (often calcic plagioclase like andesine) together with ferromagnesian minerals such as hornblende (amphibole) or pyroxene. Quartz is not common in most andesites. This mineral set defines andesite and distinguishes it from other rocks with different mineral assemblages. Granite, diorite, and basalt each have their own characteristic mineralogy (granite with quartz and alkali feldspar; diorite with plagioclase and dark minerals but less quartz; basalt with pyroxene and plagioclase and little quartz). So the minerals described are most consistent with the rock type andesite.