Franz Uibelakers was a German mineralogist. In his work, “System des Karlsbader Sinters” (1781) he presented sections of stalactites and stalagmites from the caverns of Karlsbad in Germany carefully depicted by German scientific illustrator Lachenbauer. The thirty-nine hand-colored plates are rendered in extreme detail and visualize the variations of colors encountered in the caverns. The work also includes two color wheels based on the schemes of Schiffermuller and Newton to identify the different tones of the pieces. The sections are arranged on the plates following colors and shapes affinities.
here’s the book in high-rez: https://gdz.sub.uni-goettingen.de/id/PPN726728799