
1) Arsenic mineral 2) Lead mineral 3) Orthorhombic mineral
Found on
https://www.crosswordclues.com/clue/seligmannite

Seligmanite is a rare mineral, with the chemical formula PbCuAsS3. Originally described from the Lengenbach Quarry, Valais Canton, Switzerland; it has also been found in the Raura district, Lima Region, Peru; at Tsumeb, Oshikoto Region, Namibia; and at the Sterling Mine, Sussex County, New Jersey, USA. ...
Found on
http://en.wikipedia.org/wiki/Seligmannite
No exact match found.