R727 Sample ID R727 • Cabinet C Chalk 7.07cm W x 12.087cm H x 2.56cm D • 608g Sample TypeRockRock QualitySedimentaryRock TypeOrganic CompositionCalaciteGrain SizeFineGrain ShapeRounded Grain SortingN/AAcid ReactionYesMohs Hardness 5 Somewhat shaped like a tooth. Has silicon nodules. The rock color is white on the outside and black on the inside. Description of Mohs scale here