Acanthite – Imiter Mine, Tinghir Cercle, Tafilalet Region, Morocco

 This beautifully structured acanthite thumbnail specimen illustrates how this silver sulfide mineral got its name. Due to its distinctive crystal form, Gustav Adolf Kenngott (1818–1897) named the mineral in 1855 after the ancient Greek word ἄκανθα (ákantha), meaning thorn or prickle.