Honey Color Cylinder Beads

I bought these honey-color, cylinder-shaped beads from a junkman in China. He could not tell me the exact vintage, just said "very old."

These cylinders have no distinguishing features other than their lovely color.

I have not seen them in any Chinese research material, and will like the junkman accept them as old. I am not even sure whether the stone is carnelian, agate or serpentine. Maybe as junkman says it should simply be called "yu"

I love their honey color and cool (literally) and smooth texture, so gorgeous to touch. Here are the cylinders tied with button knots into a necklace.

The central flat black bead has an eye decoration on it. Is the stone black onyx and how old?

On the reverse there are what look like traces of encrustation from some leather article. If this is not glued on, and it looks like not, then there is hope that this is a fairly old bead too.

Reverse view