[M.D. Holloway]

The same for silver as well. I guess you could make rubies or other valuable gemstones a demonination of value but the grade and purity comes into question. Gold can be smelted to be 24ct which is 99.999+% pure. Tough to do that with other precoius stuff. Some things are considered standard like oil - but the price for crude is based on a grade - light sweet is more valuable than heavy sour. Last I checked there were 400+ different grades of crude.