Great find Beth! So many of the Princess' jewels are gifts from Shipping Companies and I wonder if other royals in that period also got gifts of similar value (I remember from Princess Alice, Duchess of Gloucester's autobiography of her saying that the best part of launching ships was the jewels, but I can't recall any major jewel she would have received).

Since it is reported that Princess Anne received her Festoon Necklace from her parents for her 18th Birthday in 1968, given your suggestion, I'd think that the Grima earrings were a Christmas present, though they could have also been a personal present from Prince Philip.

I do find it odd that she hasn't worn the pendant portion for so many years, but then she has also done that with her Diamond Cluster Earrings too.