What compound was considered more precious that gold in ancient Rome?

i think it's aluminum, i found it in google

In my Google search, there was no mention of aluminum as a precious metal. Rather silver, gold and bronze were mentioned, especially in relation to use in coins.

http://www.crystalinks.com/romecoins.html
http://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Argentum.html
http://www.deadromans.com/coins/default.htm#Metals%20and%20Denominations
http://www.abc.net.au/science/news/stories/s913237.htm
http://www.answers.com/topic/precious-metal

I don't know if this will help or confuse things more for you, but I hope it helps. Thanks for asking.

In ancient Rome, the compound that was considered more precious than gold was actually purple dye, specifically the dye made from a species of sea snail called Murex. The dye was extremely rare and costly to produce, which made it highly valued. The process of extracting and creating the dye was complex and time-consuming, which added to its preciousness.

To find this answer, I recommend using reliable historical sources or academic websites that specialize in ancient Rome or Roman culture. This will ensure that you are getting accurate and well-researched information.