But IS it a mere byproduct? If it adds significant revenue, it’s no longer a mere byproduct but now part of the business proposition of the mine. About $30 billion of nickel is mined per year. About $8 billion in platinum mined per year. 30 tons of rhodium are mined per year, which at current >$900/gram prices, means the revenue from rhodium is actually HIGHER than platinum and on par with nickel.

So you could as well argue that nickel is a byproduct of rhodium (and platinum group metal) production.