It seems to me that, in view of the article by Christophe Vachaudez referred to by Franck that we should revisit this topic and try to reach a consensus.
My queries are 1 Does anyone have a copy of Hans Nadelhoffer's book to see what he says.
2. Is Clare Phillips' comment in her 1996 book (as per Christian's post in 2012) based on Nadelhoffer's 1984 book?
3. What does Christopher Vachaudez give as his source? A direct link to Cartier's archives or to Nadelhoffer's book?
Second collier
I think that everyone is agreed that the one worn by Queen Mary did come from Queen Alexandra.
It would be of great interest to all if someone had a photo of the necklace with the emeralds and rubies.