मणयो रूप्यं सुवर्णं वा घनसुषिराणां पिङ्कः ॥ कZ_०२.१४.४१ ॥
maṇayo rūpyaṃ suvarṇaṃ vā ghanasuṣirāṇāṃ piṅkaḥ
Gemstones, silver, or gold—whether made dense or hollow—fall under the category termed «piṅka».
Hollow construction enables concealment/substitution and weight fraud; classification cues inspectors to apply stricter tests and valuation rules.