Hi rikcando,
I've come across a wide variety of such coronation medals/medallions, but the two you've posted are the first aluminum pieces I've seen. Judging by the diameter and weight it would certainly be aluminum. Other metals would have to be extremely thin to have that wide of a diameter and still only weigh 6 or less grams.
I can only add that these are privately made pieces, which would have been intended for sale as novelty items. As far as value, the privately made ones are relatively cheap when compared to the much scarcer official pieces.
There were so many different pieces made privately that it is often difficult to research and attribute individual ones. The coronations were huge events throughout Britain and all commonwealth nations.
Edited by Numismat
02/18/2011 12:18 am