R686 Sample ID R686 • Cabinet B Volcanic Bomb 7.163cm W x 14.517cm H x 5.262cm D • 712g Sample TypeRockRock QualityIgneousRock TypeExtrusive CompositionMaficTexturePhaneriticColor IndexDark Clast SizeAcid ReactionMohs Hardness 8 It is a volcanic bomb with dunite xenolith. The rock is cut in half to show the green and black crystals for the dunite in the middle of the volcanic bomb Description of Mohs scale here