I don't think I'll ever get over my love of beautiful antique school slates, in significant part for the fact that almost as much as any other sort of object they bear their entire history of use and ownership on their surfaces. This I think is a very old one, late 18th/early 19th century I would guess, framed in walnut I believe and with finely carved wooden pins holding the corners together. Into one long edge on one side are the initials JEF, and just E on the other side, along with a line deeply carved into the frame all the way around, making a sort of a second frame for the slate, which itself shows all sorts of marks and scratches, all adding up to a really gorgeous patina.
13 5/8" t x 9 5/8" w x 1/2". Sound and in very good shape, with a little wiggle if one tries but holding tighter very well.