I think there are processes for man to make most any compound so long as they can nauturally stick together, but is hugely expensive for small qauntities. I guess these appear to be naturally made, but are not known to naturally exist anywhere else. Maybe the planet/entity they came from didn’t have the same full table of elements to choose from, or at least not in the same normal quantities typically found close to here, so the bindings were different. Another guess would be from far far away where maybe that is normal.
It’s from the remnants of Alderan.