The Queen held several audiences at Buckingham Palace
For more: Zimbio gallery.
I believe this is a side view of Prince Albert's Sapphire, and I have a whole scenario worked up in my head where the Ambassador from the Gabonese Republic here noticed the sapphire wonder right before this shot was taken. (I mean, I'm sure Madam Ambassador has more pressing things to notice, but you know.)
Photo: via Getty Images