An early-twentieth-century assay-office ore reference tray: cubic lead-gray galena, brassy pyrite, and resinous grey sphalerite laid out under glass with handwritten locality labels. The metallic specimens catch light as the bright elements against a deep, near-black ground.

This system distills the documented Riker-mount presentation — matte felt, real specimen luster, typewriter labels — into a dark, technical, catalog-grade interface where lead-gray and dull brass do the work.