R743 Sample ID R743 • Cabinet C Gypsum 5.597cm W x 13.176cm H x 3.025cm D • 376g Sample TypeRockRock QualitySedimentaryRock TypeChemical CompositionCalaciteGrain SizeFineGrain ShapeN/A Grain SortingWell sortedAcid ReactionNoMohs Hardness 3 It is a somewhat thin strip that is somewhat fibrous. Has a shiny look to it when light reflects off the rock. It is brown in color. Description of Mohs scale here