Definition, Meaning & Synonyms
groundmass
noun
/ˈɡraʊndˌmæs/
Definition
The finer-grained material in a rock that surrounds larger crystals.
Examples
- Granite contains a groundmass of fine-grained quartz and feldspar.
- In the lava flow, the groundmass was mostly composed of small volcanic glass fragments.
- The texture of the rock is defined by the proportion of groundmass to larger crystals.
Meaning
In geology, groundmass refers to the matrix of minerals or the finer texture in which larger crystals are embedded, often used to describe igneous rocks.
Synonyms
- Matrix
- Magma (in certain contexts)
- Precipitate (when referring to the non-crystalline structure)
