Just one question, why should "jewellery designs" look "organic"?
jewellery is quite "synthetic" in real life. Everything is done by hand (you) or/and by a machine, there is nothing "organic".
Organic looking we call in 3d world i.e. everything what follows "natural patterns" in real life, like enviroments, landscapes, trees, vegetation, sea, water, foam, fluids, VFX (dust, smoke, fire..) and all kinds of other stuff that come natural looking, organic, like in the nature.
I guess what you mean, is the word "realistic", so that the visualisations come as close as possible to the real-life products, or your vision if they´re currently not existing.
Also if you´re looking for a good artist that can follow you up in terms of what you specially need, you should take yourself time to explain the task with respect to the potential artist, instead of a confusing and sightly frustrated text aka "World, help me!". Just take you a bit time and specify what you exactly need and what you expect. Only next step will be finetuning.