R756 Sample ID R756 • Cabinet C Coal 8.555cm W x 14.65cm H x 4.952cm D • 440g Sample TypeRockRock QualitySedimentaryRock TypeOrganic CompositionOrganicsGrain SizeFineGrain ShapeN/A Grain SortingN/AAcid ReactionNoMohs Hardness 2 Completely black in color, and a dull luster. The coal is shaped somewhat like a ramp. Feels somewhat like the rock is not completely solid yet a little. Description of Mohs scale here