किञ्जल्कवर्णं मृदु स्निग्धमनादि भ्राजिष्णु च श्रेष्ठम् रक्तपीतकं मध्यमम् रक्तमवरम् ॥ कZ_०२.१३.०४ ॥
kiñjalka-varṇaṃ mṛdu snigdham anādi bhrājiṣṇu ca śreṣṭham | rakta-pītakaṃ madhyamam | raktam avaram
Gold that is pollen-colored, soft, smooth/oily in lustre, free from flaws, and brilliant is of the best grade; reddish-yellow is of medium grade; reddish is of inferior grade.
They provide observable inspection criteria for acceptance/rejection and pricing—supporting consistent assaying and reducing discretion-based corruption.