mustard-seed coal

mustard-seed coal

[′məs·tərd‚sēd ‚kōl]

(geology)

Anthracite that will pass through circular holes in a screen which measure 3/64 inch (1.2 millimeter) in diameter.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.