I'd say "Braccialetto alla schiava" or "da schiava". I heard that about earings, but a woman may help you more.
I would say "bracciale alla schiava" (you mean a wide rigid bracelet worn on the upper part of your arm, am I right?).
"braccialetto alla schiava" sounds to me a little bit strange, since usually a "braccialetto" is used to define a smaller kind of ornament.
"bracciale da schiava" sounds to me to have a negative implication, as if you were meaning that this was a bracelet used by slaves (or better, by their masters) as a symbol of their condition.
"alla" is a contraction for "alla maniera di" (braccialetto alla maniera delle schiave" and thus it eliminates negative implications.
I hope it helps,
*heidi*