Ages for Willemite at Penn Mine (Happy Jack; West Constellation; Satellite; Big Satellite; Hinkcley; Blue Jay; Meteor; Hecla; Little Satellite; Copper Hill; Penn Chemical Works; Campo Seco), Campo Seco, Campo Seco District, Foothill Copper Belt, Calaveras Co., California, USA

The cyan highlights indicate which age entries were selected as the "best" for assigning the mineral an age of 100Ma - 100Ma at this locality