amygdaloid

From Ancient Greek ἀμυγδάλη (amugdálē, “almond”) +‎ -oid.

amygdaloid (comparative more amygdaloid, superlative most amygdaloid)

1. Shaped like an almond.

amygdaloid (countable and uncountable, plural amygdaloids)

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

• mandlestone

• amygdaloidal