According to Hugh Roberts in The Queen's Diamonds the diamonds in this tiara are rose cut.
2. Strathmore tiara
Hugh Roberts says it is set mainly with rose diamonds.
3. Queen Adelaide's fringe
Hugh Roberts notes that the central bars of this jewel are set with cushion cut and pear cut shaped diamonds. I suspect that where there are round diamonds that they will be Old Mine cut. What do others think?
I think most commentators have said that QEQM was wearing it as a necklace on this occasion -- I don't have a clue!