hand sample of dolomite

background brown calcite cement cleavage collection college collegiate cooling crust crystal crystals curriculum deep discolor dolomite earth environment flat formation geo geology geoscience hand hardness hobby identification igneous impurities instrument intergrown intrusive laboratory lime lithosphere melt metallic metric mineral minerals model natural naturally non occurring opposite parallel planes plutonic properties rhombic rhombohedral rock ruler sample scale school science sheets shiny sides slow specimen specimens streaks three tinges white