snowflake obsidian
snowflake obsidian
[′snō‚flāk äb′sid·ē·ən] (petrology)
An obsidian that contains white, gray, or reddish spherulites ranging in size from microscopic to a meter or more in diameter.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.