Calcite

St. Andreasberg mining area, Goslar District, Harz, Lower Saxony/Niedersachsen  Germany

Specimen size: 5.4 × 5 × 3.6 cm = 2.13” × 1.97” × 1.42”
Main crystal size: 2.2 × 1.3 cm = 0.87” × 0.51”