Calcite
Koma
Niihori, Hidaka city, Saitama pref., Japan
Source for Quick lime and Sodium cyanide
Field of view: 5 mm. Calcite twins. Butterfly-shaped twins are formed by thin platy calcite crystals.
Recovered from an open space of a calcite vein in the Early Cretaceous calcareous sandstone.
Other localities
- Chichibu Mine (Hydrothermal Skarn, Scalenohedral)
- Horado Mine (Hydrothermal Skarn, Granular)
- Nakatatsu Mine (Hydrothermal Skarn, Rhombohedral)
- Waga-Sennin Mine (Metasomatic Skarn, Scalenohedral)
- Choshi (Andesite, Granular)
- Kodomari (Hydrothermal, Scalenohedral)
- Shobusawa (Au-Ag vein, Scalenohedral)
- Mount Futago (Limestone, Rhombohedral)
- Koma (Calcareous sandstone, Twin)
- Cotswolds (Oolitic limestone, Granular)
- Iwakake (PrP facies, Scalenohedral)