Bought this  at Estate sale! They were in this box I have no idea if this is the original box ?

Pendant and necklace marked 14K

Earrings post Stamped  what looks to be 1/20th 12k G.F ( gold filled)

So I'm not sure if this set is miss matched or not?

I'm not a jewler no expert in gold nor opals

I have no way to test the gold purity beyond visual stamps or hallmarks from manufacturer!