Perfect basal
Gedrite Magnesiogedrite , Comments: Dark gray cleavage fragment of magnesiogedrite (gedrite). , Location: Bamble, Telemark, Norway. , Scale: See Image.
K(Al,Cr) 3Si 3O 10(OH) 2Gemdat.org , Management Team (2012)
(Mg,Fe2+ ) 2[(Mg,Fe2+ ) 3Al 2](Si 6Al 2)O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)