Oh Dear. You'll never get that brooch back I'm afraid.
Lady Hester lent it to her sister, Lady Rose, who took a trip on an "unsinkable ship" which did actually sink, contrary to its ardent reputation, and its now at the bottom of the ocean.
So sorry. It will languish forever in its watery grave. The heart of the ocean. On a clear night some say you can its beauty reflected in the moonlight. Apparently, having a pint of absinthe renders its beauty particularly pronounced.