Crystals

Delicate crystals of Hematite, Fe₂O₃, and Cristobalite, SiO₂.  I had to look up the latter: "cristobalite is a high-temperature polymorph of quartz, meaning that it is composed of the same chemistry, SiO2, but has a different structure..."  Much more at the link, where it gets way more complicated than I care to blog.