The yellow/blue cube in f102v2

[MarcoP]

Hi Wladimir,
Egerton 747 is an illustrated "Circa Instans": a treaty about "simple medicines" i.e. the basic substances that can be directly used as medicines or mixed among them to produce compound medicines.
Most of the simples are plants, but a few are of mineral or animal origin (e.g. the whale from which "ambra" is extracted, You are not allowed to view links. Register or Login to view.).

This blue stone is You are not allowed to view links. Register or Login to view..
Other examples of minerals in the book are gold (aurum, 2r) and the unillustrated stones (lapis) at You are not allowed to view links. Register or Login to view..

Mineral simples from this tradition were discussed by Alexandra Marracini with reference to the Voynich manuscript: You are not allowed to view links. Register or Login to view..