Reptile Sciences Natural Sedona ProCalcium Sand is comprised of 100% calcium carbonate which feature all natural orbicular grains which prevent internal and external abrasions. In nature animals absorb calcium carbonate from water which is dissolved in the form of calcium bicarbonate. It is important for animals to have calcium carbonate absorption as it is used in the formulation of skeletons and shells. The sand also works to filter pollution and odors by clinging to your pet's waste to prevent it from scattering which allows for easy scoop removal. These silica and phosphate free sands contains essential strontium, potassium and magnesium. The fine grade quality makes it highly digestive to reduce the risk of impaction. ProCalcium Sand is suitable for snakes, reptiles, turtles and hermit crabs in terrariums. Natural Sedona ProCalcium Sand features grain size ranging from 0.1 to 0.5 mm.