Look for a stamped mark on the inside of rings, clasp of chains, or back of jewelry pieces
Check for karat marks such as 24K, 22K, 18K, 14K, 10K, or 9K
Look for purity marks such as 999, 916, 750, 585, or 417
Check for country-specific hallmark symbols or assay office marks
Inspect for a maker’s mark or manufacturer’s initials
Use a magnifying glass to read small or faint stamps
Compare the stamp with official hallmark reference charts for your country
Check for signs of wear, fading, or re-stamping on the mark
Verify the hallmark with a certified jeweler or assay office
Test the gold with an acid test or electronic gold tester if needed