pawnshop worker determines the ring of gold jewelry using the hydrostatic weighing method by archimedes' law

39aph39 archimedes authenticity business buy carat check client closeup concept control density determines euro evaluation examining fake gem glass gold hand holding hydrostatic identity inspecting items jewel jeweller jewellery jewelry lambard law lens looking luxury magnifying method money occupation pawn pawnshop popshop precious quality repair ring sale scales sell shop silver stone store using verify water weighing worker