Found in the northern Mexican state of Chihuahua, this spherulitic rhyolite is a beautiful product of volcanism and alteration. Unlike the Ocean Jasper spherulites, these primary, felsic spherulites are not silicified but altered, and display colors in shades of browns and reds.
Under the Microscope
The resulting spherulitic pattern of the rock looks incredible under the microscope. It reveals two distinct domains within the rock. In transmitted, cross-polarized light, the altered spherulites are beautiful shades of golds and browns with deep red highlights from iron oxides(Amazon Warrior design). The glassy, perlitic groundmass on the other hand is midnight black highlighted by white & gray "orbitals" of quartz and randomly placed hematite jewels(Volcanic Universe design).
In a less commonly used technique of reflected, cross-polarized light, an ephemeral glow from alteration creates a dream-like appearance. The iron-oxides again expose multiple textures within the spherulites (Bird’s Eye Dream design).