I have a small vial of what was sold to me as Violet essential oil from a stall in a London outdoor market.
It smells very strongly of Violets, but I read somewhere that the only natural source of Violet scent comes from an extract of Orris root, which apparently is very poisonous as well as extremely expensive, and hard to obtain.
I also obtained a vial of 'Wallflower oil', which, from my research, is impossible.
It does smell really nice and Wallflowery, and is very concentrated, but it MUST be a synthetic, as I don't think it actually exists.
The guy selling these 'oils', wasn't too concerned about purity either, as he used the same funnel for different oils.
The vial of Frankincense I also obtained, smells absolutely NOTHING like Frankincense, so these must definitely be synthetic.
I suspected as much when I bought them in the late 80s when I had no internet to consult, but they were pretty cheap so........
However, the flower oils do smell really nice, so I may be able to use them at some point.