Ignoramus3107 wrote:
In a pile of discarded punch blanks, I found a few "diamond
tools". These are relatively short round shanks, roughly 1/2x2 inch,
with a ~2mm diamond embedded in the end.

I know that these are useful for wheel dressing, but is there any
other use of them? Are they useful for cutting glass?

No doubt you could dress them to a point and cut glass with
them, but the diamonds are pretty crude and might crumble.
They do a dandy job of dressing alumina wheels, though.

Jon