Minerals in the Tetragonal crystal system, Trapezohedral class (4 2 2)
https://www.mindat.org/system_search.php?g=26
| Biphosphammite Cristobalite Cuprotungstite Cyrilovite Ekanite Fluorowardite |
Genkinite Kamphaugite-(Y) Lemanskiite Manganoquadratite Maucherite Retgersite |
Holonity 