Who might the silversmith be for the hallmark CA on a Hopi silver overlay necklace?

I have a good friend who passed away recently who lived through the Holocaust and I was wondering if it would be appropriate for me to wear a Star of David necklace to remember her? She was very dear to me and has gotten me very interested in converting to Judaism though I think by most standards...

I was given a perl necklace but it is broken And I want to fix it but I can't get the thread out it looks like that there is a knot or something on the thread in the perl How do I get the perls off thr thread? Please help

I would like some information on a necklace, it has "YAZZIE" stamped on the back on the pendant. It looks to be sterling and coral chocker with a coral stone of an odd shape set in sterling.