Diamond cross?

Hi all, I was going through my jewelry this evening, I came across this pretty cross.. now it's kinda dirty because it's been mixed in my assortment I've collected over the years.. only mark I can see is on the top of back cross RSB OR RSE..
do you think these could be diamonds? I think I might go get it tested tomorrow.. I forgot about this little guy..

 

Need a better pic of the mark. That looks like R53 to me?

 

Looks like 835 to me

 

I tried again.. think it's RSE??

 

CZ or crystal probably. This appears to be newish costume. A little digging tells me it's probably one of the Thai companies.

 

My new program......on my STILL GLITCHY computer.....hope it helps.....looks like RS5 to me......entirely possible the program could produce false results, too.

 

I have one kicking around somewhere that's almost identical; it's crystal and silvertone. No marks on it though.