| Domain | Definition | ||
| Mining | A jet black igneous rock consisting essentially of biotite. Near Libby, MT, such a rock has been altered to vermiculite by hot waters. (references) | ||
Source: compiled by the editor from various references; see credits. | Top | ||
| Webster's Online Dictionary |
| Domain | Definition | ||
| Mining | A jet black igneous rock consisting essentially of biotite. Near Libby, MT, such a rock has been altered to vermiculite by hot waters. (references) | ||
Source: compiled by the editor from various references; see credits. | Top | ||
