groundmass
[ ground-mas ]
/ ˈgraʊndˌmæs /
noun
the crystalline, granular, or glassy base or matrix of a porphyritic or other igneous rock, in which the more prominent crystals are embedded.
Words nearby groundmass
groundhog day,
grounding,
groundkeeper,
groundless,
groundling,
groundmass,
groundnut,
groundnut oil,
groundout,
groundplot,
groundsel
Example sentences from the Web for groundmass
Pyroxene, quartz and augite form the groundmass, as seen in section.
The Long Labrador Trail |Dillon WallaceThese lavas have groundmass textures that vary from almost holo-crystalline to glassy.
Mount Rainier |VariousIn a basal flow in Moraine Park, the slaggy and compact phases show differences in phenocrysts as well as in groundmass.
Mount Rainier |Various
British Dictionary definitions for groundmass
groundmass
/ (ˈɡraʊndˌmæs) /
noun
the matrix of igneous rocks, such as porphyry, in which larger crystals (phenocrysts) are embedded