Almandine, Quartz
Holy Terror Mine, Keystone Gold Mining District, Pennington County, South Dakota, USA
Cross section of a broken core sample from the 686 ft level of the Holy Terror Mine, consisting of metasedimentary rock (biotite-quartz-garnet-schist). The core sample measures 4.6 cm across the face and contains almandine garnets to 3 mm. Overall length of core (not shown) is 15 cm.
© Christopher Wentzell