How to check the purity of hallmarked silver jewellery?

Hallmarked silver jewellery carries the BIS mark, purity level, the word 'Silver' and a six-digit HUID that can be checked on the BIS CARE app. Silver purity is measured as a percentage, with grades from 80% to 99.9%. Common grades include 92.5% sterling silver, 90% coin silver and 99.9% pure silver.