There are no ages for Quartz at W.Y.O.D. Quartz Mine (W.Y.O.D. Qtz; W.Y.O.D. Vein; Work Your Own Diggings Mine; Cassidy Consolidated Extension Mine), Pennsylvania Mine [1] (Pennsylvania Consolidated Qtz; Pennsylvania-W.Y.O.D.; Pennsylvania Vein; Pennsylvania-Wyod; Wyod), Empire Star Group (Empire Star Mines Company Holdings), Grass Valley, Grass Valley District, Nevada Co., California, USA