तदुभयं तापनिकषाभ्यां निह्शब्दोल्लेखनाभ्यां वा विद्यात् ॥ कZ_०२.१४.३२ ॥
tad ubhayaṃ tāpanikaṣābhyāṃ nihśabdollekhanābhyāṃ vā vidyāt
Beide Arten sind durch Erhitzen und durch die Prüfung am Probierstein (touchstone) zu erkennen oder durch geräuschloses Schaben und Gravieren als Tests.
Because surface treatments (leaf, polish, color enhancement) can defeat any single method; layered verification reduces false acceptance.
Institutionalize standardized assay procedures and require objective tests (not mere appearance) before accepting, storing, or paying out precious metals.