Tough problem you have there.
Jewelry and rock hounds/collectors. Do a web search for lapidary
rough you will probably get about 86000 hits. Just start working your
way down the list. As you originally thought it to be serpentine,
that says a lot about the color, and the actinolite ID would indicate
that it is fibrous.
If you would, take pictures and send it to my email, I am in the
market for some.