Maurizio Cattelan is installing an 18k gold toilet in a restroom at the Guggenheim. How much gold is that?
The rendering appears to show a standard Kohler toilet, but in solid gold. According to Amazon, that toilet, with a seat, weighs 62 pounds, around 28kg. At around $40,000/kg, that prices out to around a million dollars right now. [When Chris Burden tried to show a stack of 100 1-kg gold bars at Gagosian in LA in 2009, it cost around $3 million, $30k/kg. But their gold dealer Allen Stanford got arrested for multi-billion-dollar fraud before he could deliver. I don't know how that ended up, but there are worse economic fates than being stuck holding gold for a few months at the beginning of 2009.]
Anyway, the thing is, porcelain and gold have different densities. Porcelain is 2.5g/cm^3, and gold is 19.29g/cm^3. So if the entire volume of porcelain in a porcelain toilet is swapped out with gold, that thing is not going to weigh 28kg, but nearly 8x more, say 210kg, which is like $8.2 million. The seat alone will weigh like 12kg, so be careful lifting it-and putting it down.
Now anyone knows you don't need that much solid gold to make a solid toilet, though. A stainless steel toilet weighs around 20kg, and steel has a density of 7.82 g/cm^3, so an identically made gold toilet would require just 50kg of gold, around $2 million.
Let's see how this all goes down.