help identifying age & stone/glass/amber? material on cufflinks please

[Pinkcoke]

These are unmarked gold tone base metal.
They have ribbon like inclusions in them like glass marbles do but the domes are irregular in shape, cold to the cheek and I don't know if that's a real insect or it just came out looking like one. Most of the material is a milky transparent white with an amber blush. Thoughts?

 

[morning-glorious]

They look like tumbled agate stones to me. I don't see amber - but various agates will be milky and have inclusions like that, and be heavy and cold to the touch.
Jen