A new phosphorus material produced by a lightning strike has been found for the first time in solid form on Earth. Although similar minerals are known to be present in meteorites and space, this transitional material, created from achemical reaction in rock, was discovered in a fulgurite, which are rocks formed by tubes or clumps of sintered, vitrified or fused debris material known as ‘fossilized lightning’.
The discovery of the material, which could turn out to be a member of a new mineral group, was made when lightning struck a tree in New Port Richey, Florida. Such a high-energy event usually makes the ground explode around the tree, creating a scar and can send an electric discharge through nearby rock, soil and sand to form fulgurites.
As reported in Communications Earth & Environment [Bindi et al. Commun. Earth Environ. (2023) DOI: 10.1038/s43247-023-00736-2], University of South Florida geoscientist Matthew Pasek bought the fulgurite from a local homeowner. He collaborated with Luca Bindi from the University of Florence to explore unusual minerals containing phosphorus, especially those formed by lightning, to better understand high-energy phenomena. Phosphate can be reduced to phosphides during high-energy events such as lightning and impacts, and here they detected that in addition to forming metal phosphides, a new compound was formed in the fulgurite.
In wet environments such as Florida, iron can accumulate and encrust tree roots. Here, not only did the lightning strike combust the iron, but also combusted the naturally occurring carbon in the tree, leading to a chemical reaction that produced the fulgurite. As Pasek said, “It’s important to understand how much energy lightning has because then we know how much damage a lightning strike can cause on average and how dangerous it is.”
It is known that lightning reduction of phosphate was a widespread phenomenon on the early Earth, and this study could show other forms of reduced minerals are plausible and many could have been important in the development of life. However, on trying to remake the material in the lab, co-principal investigator Tian Feng was unsuccessful and thinks the material will probably only form quickly under specific conditions, and that if heated too long will turn into the same mineral found in meteorites.
Although it is unlikely the material could be mined for uses similar to other phosphates as it is so difficult to re-create the conditions in which it is made, the team hope to further examine the material to assess if it could be officially declared a mineral and help increase awareness about such events.
“It’s important to understand how much energy lightning has because then we know how much damage a lightning strike can cause on average and how dangerous it is.”Matthew Pasek
A lightning strike in New Port Richey, Florida, led to a chemical reaction creating a new material, pictured here, that is transitional between space minerals and minerals found on Earth. Credit: Matthew Pasek/University of South Florida