Two blister pearls on oyster shells, Akoya?

For one money is this pair of oyster shells, each with a blister pearl. They are both in good condition, with nice regular form. They can be cut down for jewelry or displayed as is. They were part of an old rocks and mineral collection. They look like Akoya oysters. The shells are about 63 mm tall from the hinge, and the base of the blisters are about 10 mm across.