I'm pretty sure they used Monero 😂 But anyways, why didn't they use gold? It's a reserve not a medium of exchange. AFAIK Iran has gold stores, supplemental to China's gold reserves and both use the balance of trade to trade their commodities WITHOUT moving any gold. Nothing new here tbh this has been the way for centuries until Bretton Woods and until 1971. Time for reversion back to hard defined reserves and not IOUs