Definition of "augite" []

• A dark-green to black pyroxene mineral, (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6, that contains large amounts of aluminum, iron, and magnesium. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Below this were strata of trachitic breccia and augite; the formation was then seamy to an unknown depth."
• "Taken, then, a liquid which is heavy -- the most convenient is methylene iodide, whose specific gravity is 3.3 -- a fragment of zircon will sink in this, and a fragment of tourmaline will float, but a fragment of the mineral augite, whose specific gravity is also 3.3, will remain exactly suspended."
• "They are divisible into two great classes, which have received the names of diorite and dolerite, the former a mixture of albite and hornblende, the latter of augite and labradorite, sometimes with considerable quantities of a sort of oligoclase containing both soda and lime, and of different kinds of zeolitic minerals."