the world > the earth > structure of the earth > constituent materials > rock > igneous rock > [noun] > trap > amygdaloid (3)
Geol. An igneous rock, usually trappean, containing almond-shaped nodules or geodes of some mineral, as agate, chalcedony, or calc spar.
An altered basalt, commonly amygdaloidal in structure, which is characterized by the albitization of its constituent feldspars and the presence…