Wow, didn't expect this. Good catch. They underestimated the volume of olivine rock about 3 times, which means that its mining would cost about 15% of the over

Wow, didn't expect this. Good catch. They underestimated the volume of olivine rock about 3 times, which means that its mining would cost about 15% of the overall cost of mining of fossil fuels, assuming current prices of olivine rock and crude oil. This is a very rough estimate that doesn't take into account several factors, most importantly economy of scale.