A vesicle in an igneous rock, containing secondary minerals.
〔地质〕杏仁孔，杏仁石
Example sentencesExamples
Flow margins are often altered, containing abundant epidote and amygdales with quartz, calcite and/or chlorite.
Flow tops were avoided as they are almost always riddled with amygdales and show signs of alteration.
Some consist of pear-shaped segregation vesicles with amygdales at their upper margin.
If, after the lava has cooled and set, the vesicles are filled with minerals, they are known as amygdales.
Segregation vesicles are therefore distinguished from amygdales because they are infilled with chilled magma, whereas amygdales represent the infilling of vesicles from post-emplacement fluids.
Origin
Late 19th century: from French, from Latin amygdala(see amygdala).