I need help. This rock has a metallic blue luster to the outside of it (no it's not paint lol) and the only thing I came up with so far is stromeyerite. I have done every test I can on it and it all points to that. If it truly is, then it's worth a pretty penny due to its size. Any ideas?
Streak test which was steel grey, hardness test which it can be scratched with a fingernail. The metallic blue coloring is on the outside which I assume is from oxidation because I broke a small piece off and it is flat dark grey underneath. Unfortunately I don't have the stuff to do a gravity test. Any other test I can do from home?