Just to pick up on something the Countesskate said earlier about QV's small diamond crown. This particular jewel is featured in the current diamond exhibition at BP (which does also include jewellery set with pearls and diamonds, and the Delhi Durbar emerald and diamond necklace by virtue of it having the Cullinan VI marquise pendant).
The crown is minute, delicate and exquisitely crafted. I think that most photos that show QV wearing it, showing it sitting atop a veil of some description which may have helped to anchor it to her hair. It's a lovely piece and was apparently created from a diamond fringe corsage ornament, of which only the brooch (sometimes labelled as QV's waterfall brooch) remains. This brooch was also on display and was a lovely piece, worn by the late Queen Mother most notably in Beaton's portrait of her clad in a black velvet crinoline.
Thanks, Martyn, I'm not going to the exhibition until much later on in the year, but am looking forward to it greatly. I noted the sort of cushion on top of the Queen's head on which the small crown rested, covered by her veil - but that brought further thoughts, of how the cushion was anchored.........
I assume the diamond fringe corsage ornament, was the one pictured in the Winterhalter portrait? A detail is below:

However, she also seems to be wearing a diamond fringe ornament
with the small diamond crown, in the 1897 diamond jubilee photograph, detailed below:

Rather mystifying, though the latter fringe might not be diamond, of course.