So you can imagine my amazement to discover that, on eBay (and presumably elsewhere in the web's vast secondhand sector) is an entire vault's worth of jewelry that, if not exactly licensed to kill, and in no way illegal, nonetheless compels interest in and no little dread about the lady who choses to wear it.

Far more intruiging, I think, are the old versions (like the beauty at left). The Victorians apparently made quite a few of them.
Now in fairness, I don't believe those 19th century ladies were all sporting lethal jewelry with the intention to knock off their starch-collared husbands. These rings could as easily act as a holder of keepsakes as holders of arsenic.
Still, pretty cool, in a shuddery kind of way. There aren't many items of dress I could possibly wear in common with Lucrezia Borgia. If I were ever so inclined, I now know which keywords to enter.