Cumengeite
Cumengeite, also known as cumengite, is a secondary mineral that was named after mining engineer Bernard Louis Philippe Édouard Cumenge, who found the first specimens. It is easily confused with diaboleite. It is a valid species that was first described prior to 1959, and is grandfathered now, but it has been a valid species since 1893, since pre-IMA. It is the hydroxychloride of lead and copper.