Actually...

Those are very useable. I doubt you could cast them a fly rod, they'd be pretty heavy, but unless you hit a rock, they wouldn't break in normal use.

The glass 'beads' they are made out of are thick and made from a very strong and durable glass.

I've made jigging spoon type lures and some spinner bodies in the past, and they have held up well and caught lots of fish.

Good Luck!

Buddy