सुवर्णं पूर्वं निकष्य पश्चाद्वर्णिकां निकषयेत् ॥ कZ_०२.१३.१७ ॥
suvarṇaṃ pūrvaṃ nikaṣya paścād varṇikāṃ nikaṣayet
Frottez d’abord l’or sur la pierre de touche ; ensuite frottez-y l’étalon de couleur de référence (varṇikā) (pour comparaison).
It fixes the unknown sample’s streak first, then immediately compares it to a known standard under the same surface conditions—reducing dispute and manipulation.