राजतानां विस्रं मलग्राहि परुषं प्रस्तीनं विवर्णं वा दुष्टमिति विद्यात् ॥ कZ_०२.१४.५४ ॥
rājatānāṃ visraṃ malagrāhi paruṣaṃ prastīnaṃ vivarṇaṃ vā duṣṭam iti vidyāt
He should recognize silver as defective when it is foul-smelling, attracts/retains dirt, feels rough, is over-hardened/brittle, or is discolored.
Odor can indicate contamination or alloying with reactive/impure substances; the text treats sensory cues as admissible inspection criteria.