Complete single Herderite crystal with attached green mica from a little known San Diego pegmatite. Double terminated and undamaged, could be further improved with cleaning. From MINDAT: 'This is a small pegmatite deposit on private land in Chihuahua Valley, San Diego County. It is named for the botryoidal, green (lime-green, in some cases) mica---assumed to be muscovite---that occurs there. It is also the source of southern California's finest hydroxylherderite specimens.' Ex. Bob Reynolds collection.