@byteborg aawww fuk... then the likely option is A/B resin, but that's hard to diy if it's your first time and won't be fully transparent
im sure there are better more expensive options including fusing sand, but resin is accessible

@efi @byteborg How about UV-curing glue? If I'm not mistaken, it is technically resin, can fill gaps when applied in multiple layers and should be transparent.