amygdaloid

[ uh-mig-duh-loid ]

noun

, Petrology.

1. a volcanic rock in which rounded cavities formed by the expansion of gas or steam have later become filled with deposits of various minerals.

adjective

1. (of rocks) containing amygdules.
2. almond-shaped.
3. Anatomy. of or relating to an amygdala.

amygdaloid

/ əˈmɪɡdəˌlɔɪd /

noun

1. a volcanic igneous rock containing amygdales

adjective

1. having the shape of an almond
2. a less common form of amygdaloidal

Word History and Origins

Origin of amygdaloid¹

1785–95; < Latin amygdal ( a ) almond + -oid

Example Sentences

Chalcedony, apparently from amygdaloid of the trap formation, was also found at Port Warrender.

From Project Gutenberg

Quartz crystals, with chalcedony, from nodules in amygdaloid.

From Project Gutenberg

Purplish-brown epidote, with small nests or concretions of green epidote and quartz; forming a sort of amygdaloid.

From Project Gutenberg

Masses of the two former minerals were also found imbedded in amygdaloid and trap-rock, thus denoting the parent beds of rock.

From Project Gutenberg

It is found in connection with isolated blocks of amygdaloid, of primitive greenstone, and of petrosilex.

From Project Gutenberg