Tourmaline crystals to 4.5 cm with herderite twins, lepidolite and quartz from the Porcupine Pocket. The specimen is pictured on pages 142-143 in The World of Tourmaline: The Collection of Gerhard Wagner and page 164 of Mineralogical Record Vol. 54, No. 1.1, 2003, Flawless Beauty: The Mineral World of Will Johnson.