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- A plutonic igneous rock composed of 90 percent or more of feldspar mineral anorthite. Pyroxene and some olivine usually make up balance of the rock.
Source: Leet, L. Don. 1982. Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall
- A plutonic rock composed almost entirely of plagioclase, usually labradorite. It is a monomineralic equivalent of gabbro but lacks monoclinic pyroxene. CF: andesinite
Source: Dictionary of Mining, Mineral, and Related Terms