Hitch hiker mollusk

[Chefbill]

This little guy, about the size of a dime, arrived months ago as a hitch hiker on a hammer. It moved about 6 inches, up a rock, to its current location. It is creamy white with pink rays or spokes. The open edge of the shell looks almost toothed, like a Venus fly trap. It seems harmless, but I've been unable to ID. Any ideas? ?

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[Rjramos]

Looks like a scallop. Kind of like the flame scallops but white. I've heard they are difficult to keep alive long term due to feeding requirement.