I didn't have anything suitable as a "gem" for the centre... all I was able to find that was large enough was a pale blue button. So I made it into a little lucky charm for my son to attach to his backpack as he was leaving on expedition this morning. Didn't like the buttonholes so I added a smile to turn them into eyes for a happy face (if a little crooked!).
... but see what just arrived in the post...
I might just be making a few more!
What a trend you've started there Diane!
They're rather appealing.