My interpretation of the Royal Collection's comment regarding the emerald bangle on Queen Mary's right arm is that it formed part of the parure which Queen Mary had made for the Delhi Durbar.
Apart from any other consideration, there was never a parure made with the Cambridge emeralds prior to the one made by Queen Mary.
It is interesting that we have not seen this bangle worn by QEII who inherited the parure. Perhaps it is not to QEII's taste (she is not known to have worn the choker from the parure which she gave to Princess Diana). It is possible that Queen Mary willed or gave it to someone else or had another jewel made using the stones.
I wondered if the central elements in the bangle might have formed the brooches and possibly the double clasp on some pearls worn by QEQM. After looking at the thread where we discussed clasps on QEQM's pearls earlier this year, I very much doubt it, as the shape of the elements and stones look very different. See http://members2.boardhost.com/royal-jewels/thread/1421041641.html
on June 5, 2015, 4:32 am, in reply to "