What is Rare? Sure, some things are rare -- not to say many things are. ;-) But for sure there are some horological rarities that seems to be invisible:
White Gold Vintage Pocket Watches! Simply because white gold was invented in 1912 in Germany and not known and used before. And even thereafter it was rarely used since many preferred the classic yellow gold either or the much cheaper silver alloys for a non-gold appearance. See our stock of these fine and rare pocket watches here.
So, white gold was the crown of understatement and used for the most costly pocket watches back then.