"Tabique de Hostion" is a misspelling, the word they wanted to write is Ostión [1] (synonym with "ostra" for oyster). "Hostión" instead means "a large host" as a sacramental bread, and is also vulgar slang for "a heavy smack or punch" [2].
[1] https://dle.rae.es/osti%C3%B3n [2] https://dle.rae.es/hostia
One neat thing about coquina in particular is that it was used to construct the walls of the Florida fort mentioned in TFA [1, 2] where it effectively "swallowed" incoming British cannonballs, much to their bewilderment.
0: https://en.wikipedia.org/wiki/Coquina
1: https://en.wikipedia.org/wiki/Castillo_de_San_Marcos
2: https://www.atlasobscura.com/articles/coquina-fort-in-florid...