Overview
- A peer-reviewed PNAS study reports a previously unknown Ca–Cu–Si type-I clathrate preserved in red trinitite from the 1945 Trinity nuclear test.
- The crystal has a cubic framework of silicon cages that trap calcium atoms, with traces of copper and iron in the structure.
- Researchers used electron microscopy, single-crystal X-ray diffraction, and nano-CT scans to image and identify the tiny crystal inside a copper-rich metal droplet.
- The clathrate occurs in the same sample as a silicon-rich icosahedral quasicrystal reported earlier, and modeling indicates they formed in the same blast but likely not from each other.
- Analysis points to extreme, short-lived heat and pressure with rapid cooling as the cause, expanding known clathrate chemistry and offering reference data for materials science, nuclear forensics, and other high-energy events like lightning or meteorite impacts.