Definition of groundmass in English:

groundmass

Syllabification: ground·mass
Pronunciation: /ˈgroundˌmas
 
/

noun

[in singular] Geology
  • The compact, finer-grained material in which the crystals are embedded in a porphyritic rock.
    More example sentences
    • Orthoclase occurred as remnant phenocrysts in a groundmass of chloritic material resulting from alteration of iron-rich felsite cobbles.
    • The maximum length of most microbes in Group II could not be measured accurately because they are tightly embedded in the silica groundmass.
    • The wall rock was highly altered and consisted of a groundmass of pyrophyllite and fine-grained pyrite.

More definitions of groundmass

Definition of groundmass in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day skosh
Pronunciation: skəʊʃ
noun
a small amount; a little