Quartz and calcite clusterLocale: Potos Mine, Santa Eulalia, Chihuahua, Mexico Approx dimensions: 5 x 3 x 1. 5" Approx weight: 420g This quartz and calcite specimen from the Potos Mine is one of my favorites I've seen from this locale. There are two large calcite rhombs and a spherical formation covered in quartz tinted brown yellow with iron. On top are pellet like calcites that look like brown rice. Where better formed, they are small dogtooth calcite points. Quartz points