Synonyms and related words :
arenaceous, arenarious, atomic, breccial, brecciated, coarse, coarse-grained, comminuted, corpuscular, cross-grained, embryonic, evanescent, germinal, grained, grainy, granulate, granulated, gravelly, gritty, gross, impalpable, imperceptible, imponderable, inappreciable, indiscernible, infinitesimal, intangible, invisible, microcosmic, microscopic, molecular, pebbled, pebbly, rough, sabulous, sandy, shingled, shingly, subatomic, tenuous, thin, ultramicroscopic, unrefined, unseeable