hardrock

noun4

1. •
   Rock containing ore from which minerals are extracted.

   • The federal system for "hardrocks," pursuant to the Mining Law of 1872, allows the discovery, location, and development of these minerals without payment to the federal government. — 1982
2. •
   Solid, nonporous rock.

   • Its importance lies in the fact that hardrock areas cover the greater part of peninsular India. Moreover, many hardrock areas are drought-prone, making irrigation essential for reliable cropping. — 1982
3. •
   (slang) An unregenerate criminal; a bully boy.

   • Rules and regulations and strict security measures used to hold hardrocks in line work against men trying to learn responsibility for themselves. — 1959
4. •
   A type of concrete that contains relatively small amounts of aggregate relative to the amount of cement.

   • The tension test specimens embedded to 45 mm (1 - 3/4 inch) in hardrock concrete generally failed when the tensile limit of the anchor itself was reached. — 1991