Vesicular texture
From Biocrawler, the free encyclopedia.
In geology, Vesicular texture is a texture characterised by, or containing, many vesicles. Usually pertaining to extrusive aphanitic, or glassy, igneous rock. The vesicles are small cavities formed by the expansion of bubbles of gas or steam during the solidification of the rock.
A related texture is "amygdaloidal" where the volcanic rock, usually basalt or andesite, has cavities, or vesicles, that are filled with secondary minerals, such as zeolites, calcite, quartz, or chalcedony. Individual cavity fillings are termed amygdules, (American usage), or amygdales (British usage). Sometimes these can be sources of semi-precious stones such as agate.
Rock types that display a vesicular texture include pumice and scoria.
