2” grinding wheels...has anyone used or seen these?

[El JeffA]

i recently bought some old lapidary equipment. It was from a buyer of junk. He bought it, and the story told to was; the gentleman was an opal bead maker. There were saws, grinders, ultrasonic drill, bead mills, opal and parts. At the bottom of one tote were 30-2”x3/4” grinding wheels with 1/4” arbor hole wrapped in newspaper dated from the mid 70’s. They all look unused and appear to have copper/copper colored substance in the grit. See pics. I have no idea what machine these were used on or why they’re copper/colored. Any help is appreciated. Jeff A

[El JeffA]

I somehow posted same pic twice. This should be other photo.

[Pat]

Would it fit a Pixie?

[El JeffA]

The pixie has 4” wheels and (I think) a larger arbor shaft. Plus, I don’t think it predates the paper they were wrapped in. I do understand why the gentleman stopped using them since he had Highland Park 8” and Star Diamond 6” grinders that he probably added after these.

[NDK]

I don't know about the color, but I do know you can buy an arbor to chuck up in a drill that may fit those wheels.