There should be no black substance in itself, so it should be an external impurity and cannot be eaten. It is recommended to remove it and eat it.

Dried clams, also called dried clams, are made by taking out the meat of clams directly or cooking it and drying it in the sun. The dried clam is rich in nutrients, and the clam meat contains sugar, protein, fat, niacin, inorganic salts, vitamins A, B 1, B2. Clam shell contains calcium carbonate, calcium phosphate, magnesium silicate, iodine, bromine and so on. Clam meat has the functions of moistening the five internal organs, quenching thirst, softening and resolving swelling and diuresis.