Coins are far more than mere units of currency; they are physical touchstones of human history, art, and metallurgy. For collectors, investors, and museum curators, the condition of a coin—often referred to as its "grade"—is the primary determinant of both its historical legibility and its financial value [1]. A single fingerprint, an improper grip, or exposure to the wrong storage material can cause irreversible chemical degradation, instantly devaluing a rare specimen by hundreds or even thousands of pounds. next...