>  Term: blue metal
blue metal

A term used in England for a hard bluish-gray shale or mudstone lying at the base of a coalbed and often containing pyrite.

0 0

작성자

  • ed.young
  • (Milwaukee, United States)

  •  (V.I.P) 21084 포인트
  • 100% positive feedback
© 2025 CSOFT International, Ltd.