Why Oolitic Aragonite is superior to other forms of calcium supplements Oolitic Aragonite is the world's purest form of the Ocean's naturally precipitated calcium carbonate. It has a crystalline morphology of orthorhombic, bipyramid crystals with an extremely high surface area and aspect ratio giving aragonite bioavailability (calcium uptake) superior to any other calcium form. Ingredients: Oolitic Aragonite Calcium Carbonate