In an old radio parts shop recently I also got some totally unmarked diodes. A huge bag of about 100 for 50p. They don't all meter very well on my little ATmega tester and I threw a load away. The ones that did work I marked with a black sharpie along the cathode. A very slow, boring task!
I've just picked one out at random and it gets me 657mV forward, compared to a 1n270 at 319mVf and a jellybean 1n914 at 690mV, I'd suggest they were silicon. Still, I'm sure they'll come in handy SOME day...