An electron micrograph of volcanic sublimates (minerals) in natural colors. Abundant micron-sized crystals of thallium iodide TlI (an unnamed mineral in fumarolic incrustations, Mutnovsky volcano, Kamchatka). The mineral has two polymorphs – yellow and red, with a gradual transition between the two. The crystals are located on a substrate of altered rock. Image size is 700 microns along the long side.