Vintage pair cufflinks- Not sure of metal- maybe silver or silver plate or ???  One is shown.

No makers mark. 
Black material (stone?  jett?  hard plastic?) that appears to be drilled to accept the rhinestone.  I think the rhinestone is glass- it doesn't feel like plastic.  But, no promises there.  USED condition.  No rust.  Some scuffing- typical wear.  Ask questions if you have any- I am not an expert and may have missed something. 
If you need additional photos or have any questions, please let me know.  I'll be happy to try to help.
From my non smoking home.
Check my stuff for more beautiful items that catch my eye!  I have a pretty eclectic collection of stuff and add new items almost daily.