| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Hard rock | Geography | Rock whose components are tightly bound together. Source: European Union. (references) | |
| Hard rock | Health | Crack Cocaine. (references) | |
| Hard rock | Mining | A. A term used loosely for igneous or metamorphic rock, as distinguished from sedimentary rock b. A rock that is relatively resistant to erosion c. Rock that requires drilling and blasting for its economical removal. Cf: soft rock. (references) | |
| Hard rock minerals | Mining | Solid minerals, as distinguished from oil and gas, esp.those solid minerals found in hard rocks. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
