R722 Sample ID R722 • Cabinet B Lava 14.907cm W x 5.958cm H x 4.185cm D • 484g Sample TypeRockRock QualityIgneousRock TypeExtrusive CompositionMaficTextureVesicularColor IndexDark Clast SizeAcid ReactionMohs Hardness 8 It is rectangular shaped. Has a somewhat smooth/glassy top, and vesicle bubbles of varying sizes on all the remaining sides. Description of Mohs scale here