A calcium silicate hydrate mineral (Ca/Si=0.83) widely recognised as one of the base structures for C-S-H.
E. Bonaccorsi, S. Merlino, A.R. Kampf, The crystal structure of tobermorite 14 Å (plombierite), a C-S-H phase, J. Am. Ceram. Soc. 88 (2005) 505–512. doi:10.1111/j.1551-2916.2005.00116.x.