R742 Sample ID R742 • Cabinet C Concretions 6.062cm W x 18cm H x 2.122cm D • 356g Sample TypeRockRock QualitySedimentaryRock TypeChemical CompositionSilicaGrain SizeN/AGrain ShapeN/A Grain SortingWell sortedAcid ReactionNoMohs Hardness 3 The rock is gray and uniquely shaped. It has circular indentations from where the sediment settled and the rock is somewhat a chain of those circular indentations. Description of Mohs scale here