R812 Sample ID R812 • Cabinet X Lava Column 5.009cm W x 10.565cm H x 2.658cm D • 222g Sample TypeRockRock QualityIgneousRock TypeExtrusive CompositionMaficTextureColor IndexDark Clast SizeAcid ReactionMohs Hardness 5 The rock looks somewhat like the tip of a knife. One side of the rock is thinner than the other side. Description of Mohs scale here