Alginic acid, is a naturally occurring polysaccharide found in brown algae. It is hydrophilic. With metals such as sodium and calcium, its salts are known as alginates. Its color ranges from white to yellowish-brown and may appear as filamentous, granular, or powdered forms. Its typical molecular mass ranges from 10k to 600k; however alginate is often characterized and presented with viscosity, instead of molecular weight.