Amygdules or amygdales (/ əˈmɪɡdjuːlz, - deɪlz /) form when the vesicles (pores from gas bubbles in lava) of a volcanic rock or other extrusive igneous rock are infilled with a secondary mineral, such as calcite, quartz, chlorite, or one of the zeolites. [1] .

Amygdule, secondary deposit of minerals found in a rounded, elongated, or almond-shaped cavity in igneous rock. The cavities (vesicles) were created by the expansion of gas bubbles or steam within lava. Some amygdules consist partially of lava, …

An amygdule is “a gas cavity or vesicle in an igneous rock which is filled with such secondary minerals as zeolites, calcite, quartz, or chalcedony.” Such a rock is said to be amygdaloidal. Amygdules form when fluids containing dissolved minerals flow through a rock and deposit the minerals as solids in the vesicles.

The meaning of AMYGDULE is one of the rounded nodules occurring in an amygdaloid.

Using a canoe or small boat, watershoes and plenty of time, walk the shore and watch for veins and amygdaloids. Observe the interiors of basalt flows where vesicle cylinders, pegmatites, joints and veins may expose these distinctive minerals (see diagram).

Amygdaloids are simply vesicles that have been filled in with a secondary mineral long after the flow cooled. Such secondary minerals are commonly white: quartz, calcite, or zeolite. (A secondary mineral is one that formed after the rock originally formed.) This is a fine example of a vesicular basalt.

Amygdules or amygdales ( / əˈmɪɡdjuːlz, - deɪlz /) form when the vesicles (pores from gas bubbles in lava) of a volcanic rock or other extrusive igneous rock are infilled with a secondary mineral, such as calcite, quartz, chlorite, or one of the zeolites.

Amygdule is more common in American usage, while amygdale is more common in British usage. Phenocryst – Crystal larger than the rock grains that surround it in an igneous rock; Volcanic gas – Gases given off by active volcanoes

Define amygdule. amygdule synonyms, amygdule pronunciation, amygdule translation, English dictionary definition of amygdule. n. A small gas bubble in igneous, especially volcanic, rock filled with secondary minerals such as zeolite, calcite, or quartz.

A vesicle or vapor cavity of volcanic and occasionally of intrusive rocks, which has become filled (partly or completely) with secondary products usually of late magmatic origin, such as zeolites, chlorite, forms of silica, and calcite. Amygdule is the diminutive of amygdale, and consequently the terms are not strictly synonymous.