If you plan on ordering in stainless, 1) it has to be 3mm thick. and 2) all that unsupported geometry will probably make it unprintable.
If you plan to wait for silver, the previous minimum thickness was .5mm but you would still have issues with the unsupported geometry I believe (they print in wax, then use that to cast the silver)Your friendly neighborhood Moderman
What it means is, in stainless there is a green phase. Where the model is very fragile. They have to pack a support material around it to bake it. To pack around the swirls of the pendent would be difficult without breakage, and during the firing process they would most likely sag. I think it would be very difficult to get your intended result in stainless. I'm not as sure about silver, it may be more doable. But we'll have to wait to see the new guidelines when they are released. Your friendly neighborhood Moderman