sky / shell exchange
Each sky is graded by luminance, cloud density, and the particular shade of blue at the zenith. Dawn skies command premium. Overcast is traded at volume.
Sunset gradients are futures: you invest in the probability of a particular color sequence appearing at a particular latitude. The best traders can predict the exact moment coral becomes gold.
Shells are indexed by their golden ratio proximity. A perfect logarithmic spiral is the market's treasury bond -- stable, beautiful, eternal.
The inner chambers of shells refract light into spectra no painter could mix. Nacre quality is measured in lux per angle. The finest specimens glow from within.
The rarest asset is the moment where atmospheric light enters a spiral chamber and becomes color itself. This is the convergence -- where both markets find their single price.