from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An exposed, oxidized portion of a mineral vein, especially a rust-colored outcrop of iron ore.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. decomposed rock, usually reddish or ferruginous (owing to oxidized pyrites), forming the upper part of a metallic vein
from the GNU version of the Collaborative International Dictionary of English
- n. Decomposed rock, usually reddish or ferruginous (owing to oxidized pyrites), forming the upper part of a metallic vein. Called also iron hat.
from The Century Dictionary and Cyclopedia
- n. In mining, the ferruginous quartzose material which often forms a large part of the outcrop of a lode in which the metallic contents at depths exist chiefly in the form of sulphids, among which pyrites, a combination of sulphur and iron, is rarely wanting, and is often present in large quantity.
Cornish gossen, from gōs, blood, from Old Cornish guit.(American Heritage® Dictionary of the English Language, Fourth Edition)