These electric-blue abstract shapes in a desert of brown rocks are mineral ponds in Moab, Utah. They’re part of a mine that produces a potassium-rich salt called muriate of potash, a key ingredient in fertilizers.
The salt is pumped to the surface from deep underground and dried in giant pools. Its vivid blue color is the result of dye, added to darken it, so that it absorbs more sunlight and evaporates more quickly. After 300 days, the water is gone and the salt remains.
Gemasolar is a solar power plant in Seville, Spain. The 2,650 mirrors radiating out in concentric circles focus the Sun’s energy to heat salt in the tower in the middle. It gets so hot that it melts. It then circulates to a storage tank, where it’s applied to produce steam and generate electricity.