Mineralogy and Geology. The cropping up or out of a stratum, vein, etc. Obsolete.

Decomposed rock, of a reddish or ferruginous colour (due to oxidized iron pyrites), forming a part of the ‘outcrop’ of a metallic vein.

Mining. = gossan, n. a. Cf. iron cap n. at iron, adj. compounds 2.

technical. Mining. ‘The oxidized or decomposed outcrop of a vein or coal-bed, more frequently the latter.’ (Raymond Mining Gloss.) Also, radiated…

= gossan, n. a; cf. iron hat, n. 2.

(see sense 3a).

plural. A name for the inferior qualities, leavings, or residue of any product; foots, bottoms. A decomposed outcrop of a vein or bed.

(a) see top-fruit n.; (b) Mining an outcrop.