a member of the chlorite group, rhombohedral in habit.
Also pen·nine [pen-in, -ahyn] /ˈpɛn ɪn, -aɪn/.
Origin of penninite
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a bluish-green variety of chlorite occurring in the form of thick crystals
Word Origin for penninite
C20: from German Pennin Pennine (Alps) + -ite 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012