The term "half-breed" is reserved, generally, to admixed copper and half silver specimens, mostly from the upper peninsula of Michigan (I can't really think of another locality where this occurs). Rarely you get a nugget which also shows the combination of the two native elements, melded together under enormous heat and pressure in the distant past. This rounded nugget seems to be primarily silver, although they are well admixed. It has obviously been naturally tumbled or water worn in the deposits. 133 grams (more mass than it seems from the size!) .