Vintage gold plated etched Chinese export black onyx? Hinged bangle bracelet

Vintage gold plated etched Chinese export black onyx? Hinged bangle bracelet with safety chain The gold held under 10k acid but was eaten by 14k(I don’t have 12k) However- some spots of the safety chain have slight wear- so this is earth gold plated or the safety chain is just gold tone The metal is very hard- tough to scratch I’m not sure if the black is onyx or not- this is one small flea bite in the onyx Overall the bracelet is beautiful- the catch hold well and it feels very nicely constructed