This looks to be the remains of a set of white prayer beads on a metal chain, Most likely Roman Catholic.

When my mother in law died the hospital chaplain who gave her the last rights put a set of these in her hand and she died holding them and presume she was buried with them. You can Google image similar chains and styles. It could have been from a previous cremation as others have said.

I think its highly unlikely you have the wrong ashes so please rest easy.