Hand Sample: Lapilli tuff containing pieces of pumice (HA-23) and trachyte obsidian (HA-22) ranging in size from 0.1cm to 1.5cm. Clasts are held together in light-colored ash. Sample surface crumbles when handled. Lapilli describes the size of theā¦
Hand Sample: Aphanitic dark gray trachyte. Sample contains zones with abundant tiny vesicles (less than 0.1cm in diameter), however the majority of the sample does not contain any vesicles or phenocrysts.