Niikoba
Hiikoba, Hizen village, Karatsu city, Saga pref., Japan
Occurrence
Minerals in vesicules of the late Pliocene (3 Ma) alkali basalt, a member of the Higashi-Matsuura Basalt erupted on the ground surface. The type locality of Kimuraite-Y, Kozoite-Nd, Kozoite-La, and Lanthanite-Nd.
Outcrop of alkali basalt of the Higashi-Matsuura Basalt. The massive pale gray host is alkali basalt. A part of vesicules are filled with white calcite and aragonite with minor amount of Nd- and La-bearing minerals.
Reported Minerals
- Kimuraite-Y
- Kozoite-Nd
- Kozoite-La
- Lanthanite-Nd
- Calcite
- Aragonite
- Lokkaite-Y
- Hyalite
Mineral Assemblages
- Aragonite - Kimuraite-Y