

The oxide layer forms within seconds, like aluminium and sodium (the two elements surrounding it), and even if you scraped it off and stuck it on your tongue, it isn’t going to react quickly enough to do you any damage. It will probably taste slightly bitter, like licking baking soda. I have some downstairs. Shall I test it and take a video of the results?
What? No. The Leidenfrost effect would apply. You could pour a few milliliters of liquid helium over your tongue and it would boil on contact. You just need to make sure to minimize total contact time.