Citation: Finney, J. J.; Kumbasar, I.; Konnert, J. A.; Clark, J. R. (1970). Crystal structure of the calcium silicoborate, howlite. American Mineralogist, 55, pp. 716-728.
Formula: B5 Ca2 H5 O14 Si
List type: noninterleaving
List: 2D
Basis: (0;1;0 0;0;1)
Dimensionality: 2
Formula: B20 O56 Si4 (B5 O14 Si)
Multiplicity: 1