R721 Sample ID R721 • Cabinet B Lava Column 6.067cm W x 14.752cm H x 3.889cm D • 676g Sample TypeRockRock QualityIgneousRock TypeExtrusive CompositionMaficTextureColor IndexDark Clast SizeAcid ReactionMohs Hardness 5 It is shaped like a long 3D pentagonal. Description of Mohs scale here