I see, you were challenging the "The only way" part of the statement. Yes, any metal alloy or hollow body with a density matching gold could be used to pass den

I see, you were challenging the "The only way" part of the statement. Yes, any metal alloy or hollow body with a density matching gold could be used to pass density based tests. The natural choice is the cheapest metal of sufficient density -- tungsten. Platinum was historically used to dilute gold by alloying before it became valuable in its own right and chemical tests improved. "Gone Platinum: Contraband and Chemistry in Eighteenth-Century Colombia" https://www.vianolavie.org/wp-content/uploads/sites/5/2015/06/Gone-Platinum.pdf https://www.vianolavie.org/wp-content/uploads/sites/5/2015/0...