Structures, systems, and methods verify the authenticity of a precious metal unit. A "ping bar" is designed to have a distinctive sound only if authentic and unadulterated. A "waffle bar" is shaped to discourage adulteration, damage, or counterfeiting and to facilitate easy core sampling and assay of the constituent metal's purity. Reeded edge features may additionally be employed to discourage tampering. An RFID device and a global registry system verify various attributes and ownership of the precious metal units.