Titanium or Stainless

What's the best way to tell if you have Titanium or Stainless Valves or valve springs? Isn't stainless slightly magnetic?

 

You can pick up a tit valve and a stainless and tell the difference in weight.
If you don't think you can weigh them.

 

Most common stainless steel is non-magnetic, so is titanium. If you grind the valves, the titanium valve will have exploding type sparks, while the stainless steel will have virtually none.