SG Heritage Dictionary

Amygdaloid [Noun] Webster's Dictionary 1828

Toad-stone; a compound rock, consisting of a basis of basalt, greenstone or some other variety of trap, imbedding nodules of various minerals, particularly calcarious spar, quartz, agate, zeolite, chlorite, etc. When the imbedded minerals are detached, it is porous, like lava.

Amygdaloid [Adjective] Webster's Dictionary 1913

Alt. of Amygdaloidal

Amygdaloid [Noun] Webster's Dictionary 1913

A variety of trap or basaltic rock, containing small cavities, occupied, wholly or in part, by nodules or geodes of different minerals, esp. agates, quartz, calcite, and the zeolites. When the imbedded minerals are detached or removed by decomposition, it is porous, like lava.

Amygdaloidal [Adjective] Webster's Dictionary 1828

Pertaining to amygdaloid.

Amygdaloidal [Adjective] Webster's Dictionary 1913

1. Almond-shaped.

2. Pertaining to, or having the nature of, the rock amygdaloid.