groundmass
/ˈgrau̇n(d)-ˌmas/ (ame, mw)
groundmass — 名詞
1. in a porphyritic rock, the small-grained or glass-like material surrounding the
基質；石基
斑狀岩中包圍大顆晶體的細粒基底
in a porphyritic rock, the small-grained or glass-like material surrounding the larger crystals you can see with the naked eye.
Under the microscope, Samir saw bright crystals of quartz set in a dark groundmass.
在顯微鏡下，Samir 看見明亮的石英晶體鑲嵌在深色的基質之中。
collocation: set in a (dark/fine) groundmass
The groundmass of this lava sample is so fine that it looks almost like glass.
這塊熔岩樣本的基質非常細，看起來幾乎像玻璃一樣。
pattern: the groundmass of [rock sample] is [texture]
Tariq's students learned to tell the large crystals from the surrounding groundmass.
Tariq 的學生學會辨別大顆晶體與周圍的石基。
In many volcanic rocks, the groundmass cooled quickly and never formed visible crystals.
許多火山岩的基質冷卻太快，因此沒有形成肉眼可見的晶體。
Ife pointed at the pink feldspar grains floating in a pale grey groundmass.
Ife 指著漂浮在淺灰色基質中的粉紅色長石顆粒。
- matrix
broader term used across petrology and sedimentology; groundmass is reserved for the fine material around phenocrysts.
- mesostasis
the very last material to crystallise between earlier crystals; a narrower technical subset of the groundmass.
- phenocryst
the large visible crystals embedded WITHIN the groundmass — the contrasting component, not the same field of view.
文法句型
the groundmass of [rock type]
用法筆記
Almost always uncountable and used in petrology or igneous-rock contexts. Subject of the surrounding sentence is usually a rock sample, thin section, or specimen rather than a person.