TB62AG9: A novelty at Tucson 2017. Thick lenticular Calcite crystals with very well defined faces and edges. They are translucent with parallel growths and an easily visible interpenetration twin. They have grown around acute scalenohedral crystals of a first Calcite generation that are coated by Palygorskite. The related black material are manganese oxides.
Palmarejo Mine, Palmarejo, Municipio Chinipas, Chihuahua  Mexico (10/2016)

Specimen size: 18.3 × 10.7 × 10 cm = 7.20” × 4.21” × 3.94”

Main crystal size: 6.5 × 4.8 cm = 2.56” × 1.89”