Phosphorus is one of the more common elements on Earth. It's more common than carbon, sulfur, or nitrogen (to name 3 other elements essential to life): https:/

Phosphorus is one of the more common elements on Earth. It's more common than carbon, sulfur, or nitrogen (to name 3 other elements essential to life): https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth... Lower grade phosphorus-bearing minerals could also be refined to concentrate the phosphorus. But there's little current incentive to do so when the tried-and-true process starting with phosphate rock will be adequate for a couple more centuries.