covelline
/koʊˈvɛlaɪn/
noun
- A rare blue or indigo mineral consisting of copper sulfide, often found in copper ore deposits.
- Under the microscope, the covelline sample showed a striking iridescent sheen.
- The miner discovered a vein of covelline deep in the copper mine.
- Covelline is prized by collectors for its deep blue color.