The descriptions I have read say that Mary of Modena's coronation crown was never used again and resides in the Museum of London. Her state crown was used as a coronation crown by succeeding queens, Including Mary II as queen regnant. But I still haven't read a really convincing description of Queen Charlotte's crown, other than it was set with her own diamonds (later stolen in Ireland). I did read that some of the empty Hanoverian crowns were sold to a jeweler in the 1830s and were only recently returned to Queen Elizabeth II. Those seem to have included the frame of Queen Adelaide's new crown; therefore it was not available for Queen Alexandra to consider.