hydrogrossularite

\\| ̷ ̷ ̷ ̷ at hydro-+\ noun

Etymology: hydr- + grossularite

: a mineral Ca₃Al₂(SiO₄)_3-x(OH)_4x, consisting of silicate of calcium and aluminum in which silicon is partly replaced by hydrogen with x near 1/2 : one of the hydrogarnets intermediate between grossularite (x.0) and hibschite (x.1)