I posted that information on the Royal Jewels of the World Message board some years ago.
Since the board's subscription lapsed a while ago, links to a lot of the posts have been lost. While it is still possible to trace those posts, it takes quite a bit of effort. I have given up tonight.
Below is the brooch worn by the Duchess of Cornwall.
Below is one image of Queen Mary wearing (I think) the same brooch.
I believe that Queen Mary had another aquamarine brooch which has since been worn by QEII, but I won't confuse the issue by posting it now.
Previous Message
I missed the post about the aquamarine brooch worn by the Duchess of Cornwall being from Queen Mary and can't find it using the search, do you have a link to it that you could post please?
Previous Message
I believe that the brooch on her hat is the one now worn by the Duchess of Cornwall which I identified some years ago from other photos.