from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A usually black or banded, hard volcanic glass that displays shiny, curved surfaces when fractured and is formed by rapid cooling of lava.

from The Century Dictionary.

  • noun A volcanic rock, in a vitreous condition, and closely resembling ordinary bottle-glass in appearance and texture.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Min.) A kind of glass produced by volcanoes. It is usually of a black color, and opaque, except in thin splinters.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun mineralogy a type of black glass produced by volcanos
  • adjective poetic black

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces


from The American Heritage® Dictionary of the English Language, 4th Edition

[Latin obsidiānus, misreading of obsiānus (lapis), Obsian (stone), obsidian, after Obsius, a Roman who supposedly discovered it or a similar mineral.]


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  • the obsidian gleam of crow

    suzanne, suzzanagig jig

    December 29, 2006

  • more a liquid than a solid:will last only for about 25 million years

    August 11, 2008

  • Often used to describe the colour of eyes.

    Or perhaps that's just in the fanfic I read.

    I'm sure I've read it somewhere else, though.

    August 11, 2008

  • I love this word, but now every time I see it I think of Firesign Theatre. "I lifted the heavy obsidian doorknocker... Hey in there! Open up! Your doorknocker fell off!"

    August 11, 2008

  • Heehee!

    August 11, 2008

  • Seems ugly to me - obscene, sinister, morbid, reptilian thing.

    August 12, 2008