u/Adorable-Version8783

Hi everyone!
As the title says, I would like to try to separate these two stones from the glue that attaches them (it looks like silicone with a rubbery consistency of what little I managed to remove) initially I tried with a spatula and it's left but a little, then I can't advance, then I tried with a nylon fishing line I had better results than the spatula but then the thread broke in my hands, maybe because it made too much resistance, can anyone help me? Honestly I don't know what else to do