Thanks The Royal Watcher. Now that I have the benefit of your eagle eye, I can see that the lower element is composed of diamond chain links.

Thanks for the other photos.

The only other head jewels I have seen are the previous Marchioness (in 1979)

Edit: Thanks to 992234117 I now know that the photo below is not of the Marquess and Marchioness of Bath but of the Marquess and Marchioness of Bristol. Apologies for confusing people.



and Lady Silvy Thynne wearing what looks like an emerald necklace mounted on a tiara frame.



Hopefully the current Viscountess Weymouth will wear more of the family jewels in the future.