San Francisco, United States.

"Should you find these under your microscope, you’ve discovered something as valuable as gold– these diatoms absorb CO2 and help produce 20-30% of Earth’s oxygen. Collected from the San Francisco Bay, the photographer notes that these diatom’s colors are the result of the light being routed around the sides of the slide in the microscope, then refracted by the structure of the diatom wall."