For the first time, a clathrate crystal—a cage-like structure trapping other atoms—has been found as a byproduct of a nuclear blast.
Researchers have identified a previously unknown type of clathrate crystal in a sample of red trinitite, the glassy material created by the first nuclear bomb explosion on July 16, 1945, at the Trinity test site in New Mexico.
Discovery and Composition
The crystal is a calcium-copper-silicon clathrate, characterized by a cage-like arrangement of silicon atoms that traps calcium and copper atoms. It was discovered within a copper-rich droplet embedded in the red trinitite. The sample's distinctive red coloration comes from metallic droplets—remnants of the test tower and equipment—that vaporized during the explosion and then mixed with melted desert sand.
This marks the first known occurrence of a clathrate structure formed as a byproduct of a nuclear blast.
Formation Conditions
The clathrate formed under extreme transient conditions. Multiple sources report that temperatures exceeded 1,500°C (approximately 2,700°F) and pressures reached between 5 and 8 gigapascals, followed by rapid cooling. The crystal demonstrates how nuclear explosions can create metastable phases—structures that are highly difficult to reproduce in a laboratory setting.
Methodology
To identify and characterize the crystal, the research team employed single-crystal X-ray diffraction and nanoscale tomography. Density functional theory calculations were then used to analyze the clathrate's atomic structure. The study also investigated whether this clathrate could be a precursor to a quasicrystal previously found in similar trinitite material. Mathematical analysis suggested the two structures formed independently, despite sharing similar compositions.
Significance
This discovery highlights how high-energy events—such as nuclear blasts, lightning strikes, or meteor impacts—can generate new mineral phases and crystal structures. Researchers noted that these findings expand the understanding of how matter organizes under extreme shock conditions and may provide valuable forensic tools for investigating explosion sites.
Publication
The findings were published in the Proceedings of the National Academy of Sciences (PNAS). The lead author is Luca Bindi, a mineralogist at the University of Florence.