Minerals in the Hexagonal crystal system, Trapezohedral class (6 2 2)
https://www.mindat.org/system_search.php?g=19
| Brockite Edgarite Grayite Kalsilite |
Quintinite Rhabdophane-(Ce) Rhabdophane-(La) Rhabdophane-(Nd) |
Rhabdophane-(Y) Russoite Santanaite Virgilite |
Holonity 