I teach math at the
Dana Hall School in Wellesley, MA. In the 2013-14 school year, my Advanced Topics students and I dreamed up a "secret society" for math enthusiasts at our school. We had lots of fun brainstorming ideas for how it would operate and engage with the student body as a whole, but it never really moved beyond the planning phase. However, I did design a cryptic symbol to stand for the group (which the girls printed and discreetly posted in random locations around campus). It was simple and geometric, consisting of five circles, but it also had echoes of the moon-and-star that has become an unofficial symbol of sisterhood among Dana Hall alumnae.
I thought it would make a cool pendant.
So the secret may be out, but you can still become an honorary member of...
The Hypatia Society.
Available in several plastics and metals.