For her silver wedding anniversary Queen Alexandra was given a set of pearl and diamond earrings by Lord Rothschild and Alfred Rothschild. The first description I found years ago described them as solitaires, which left me somewhat baffled. Then, I wondered (and posted my suggestion) that these were the larger diamond and pearl earrings worn by Queen Mary and QEII. Others disagree.
The descriptions of the gift. (1)
(2)
Here the earrings are simply referred to as studs.
(3)
This report talks about the flawless round pearls.
Evidence that Queen Alexandra wore these 1909
1909 at a ball given by the US Ambassador, Whitelaw Reid in 1909.
This description comes from the same occasion: the ball given by Whitelaw Reid in 1909. It does not mention the pearl earrings. It is the description of HM's dress which is of interest on this occasion.
The only image I have found where I think that Queen Alexandra is wearing these pearls is this --