Last one is dreadful, no doubt.
Top two, well, the all-black one is best. Quite classy, considering the disastrous name
Are you Jewish? Is the shop for Jewish customers? If not, that's the impression it gave me - slightly bizarre. I'd take that name nowhere.
However, I'd keep the all-black logo (diamond) and re-think the name.
Or how about a very deep blue for the text and a silver-colour diamond?
Who are the people involved in starting the shop? Perhaps the best idea is to use their names, or their names in some bizarre combination.
I'm not sure.
Or an adjective that describes jewellery? Sparkle? Gold? Golden Age? I'm not sure. How upmarket is the shop? Cheap or expensive?
Also, Jewelry is the American spelling, Jewellery the English. Best off without the word, I reckon.
However, I think the black and white logo is classy