I found that I had a more complete description of the Glasgow pearls. It says that the necklace had a round clasp with nine diamonds with a diamond on either side.



I don't think that matches what can be seen in the photo of QEII with the Diamond Diadem. And I think the necklace HM is wearing has more than 51 pearls.





As for whether the other photos Franck and Thomas posted might include the Glasgow pearls, I cheerfully admit that I cannot tell. I am totally confused at present.