Re: [math-fun] Iridium & Indium (inside future analogue of light bulbs?)

Iridium is 40x rarer than gold

There appears to be some variation in online crustal abundance numbers for iridium and gold, with the 40-fold abundance of gold over iridium being an order of magnitude larger than many. The ratios from three separate sources on Wikipedia's 'Abundance of elements in Earth's crust' page range from 3.7 to 7.8 times as abundant.