Happy October! October’s birthstone is opal, which is pretty cool, but I’d sure like to know why.

While birthstones were originally lifted from the armor of Moses’ older brother, they differed widely across countries and religions. In 1912 the National Association of Jewelers wised up and put together an official list. It’s been revised a few times since then, but mostly to add weird-named secondary stones like sardonyx and chrysoprase.

If you’re feeling a little capricious and want to buck the established order, you could always go for your zodiacal stone or even a day of the week stone. Happy Ruby Tuesday!

New Classes

We’re launching a series of fall tree identification walks, just in time for all that autumn color to hit. You’ll learn terminology—branching patterns, fruiting bodies and more—and get in lots of practice time examining street trees out in the neighborhood. See all the dates, and sign up here.

And, lastly, we’ll be hosting another class with the folks at Babeland on Sunday, October 21st. The details are a little too scandalous to publish in this email, but you can read all about it and sign up right over here.

The Society for the Advancement of Social Studies

S.A.S.S. meets tonight (Tuesday, October 2) with three short lectures on explorers not named Christopher Columbus. It all goes down at Public Assembly in Williamsburg. Doors at 7, drink specials all night, and more details here.

Scholarly yours,

Jen, Soma & Anna