These neckpieces have been inspired purely from industrial tools. The holey cheese block looking pieces you see here, are usually random brass slabs, that are used to check drill bit sizes before the workman actually drills through metal.
I happened to have chanced upon these abstract cut pieces many months back at a hardware factory and was fascinated at how gorgeous they looked without meaning too.
Some things are even more beautiful because they are simply so unaware of their own beauty.