07-27. Gypsum #5.
Gypsum is the most challenging mineral I worked on so far – color wise!
Its crystal has a pleasant well-organized geometry, and a dynamic symmetry – but either black and white or color, no hue seems to hit the right tone. Almost there – but never really vibrating like so many other minerals I studied did once I found the right balance between intensity and transparency.
Each mineral has its own secret, but this one would be a good candidate for a challenging class on color theory.
From a resource by W. Wooster.