Queen Elizabeth turns 80 this month and the royal website lists 80 facts about Her Majesty. One is that her jewelry collection includes “the largest pink diamond in the world.” I confess that I’ve actually studied her treasure trove of jewelry, thanks to a few books on the subject, and I don’t recall a pink diamond. I’d be one to remember a pink jewel. But the web is its own treasure trove, so this information hole is easy to solve. Assuming she hasn’t recently acquired a new pink stone, the diamond must be the Williamson Pink, nicely set in a flower brooch. The round-cut gem weighs in at 23.6 carats. However, the Darya-i-Nur (Sea of Light) diamond, part of the Iranian royal jewels is estimated to be 182 to 186 carats. The Steinmetz Pink is 59.60 carats, cut down from 100. The Williamson Pink diamond weighed 54.5 carats prior to being cut, so there must be a missing qualifier to that “largest” fact.