Peltier ?

[drizzlermibs]

Another attempt at a "pair" Peltier on the left is one I have had, with trace amounts (horsehair) of oxblood. The one on the right is new. I was hoping another Peltier with oxblood; but as the "streak" is below the surface I am wondering if metallic? Or simply can't be determined.

 

[cheese]

I doubt if it's metallic. I don't think I have ever seen metal on a marble go below the surface. Not sure if it's oxblood or not though...