If commodity money was still used nowadays, what items do you think would be used as a medium of exchange? Why?

If commodity money was still used nowadays as a medium of exchange, common commodities that would be used would be rare metals such as gold, silver, or platinum as well as jewels such as diamonds or pearls. In addition other resources that are easily transported and valuable could also be used this could include oil, coal, or natural gas, however, smaller resources would normally be preferred over large ones.