R720 Sample ID R720 • Cabinet B Tuff 15.132cm W x 17.5cm H x 10.214cm D • 5570g Sample TypeRockRock QualityIgneousRock TypeExtrusive CompositionFelsicTexturePyroclasticColor IndexLight Clast SizeAcid ReactionMohs Hardness 5 It is a big somewhat rectangular rock. You can vaguely see lines from the different volcanic outbursts. It is varying shades of light greyish-brown color. Description of Mohs scale here