A University of South Florida professor discovered that lightning that struck a tree in a New Port Richey area created a new phosphorus material. It was discovered in a rock, the first time in solid form on Earth, and it could be a member of a new mineral group.
We have never seen this material occur naturally on Earth—minerals similar to it can be found in meteorites and space, but we've never seen this exact material anywhere.
Matthew Pasek, Professor, School of Geosciences, University of South Florida
In a recent study published in Communications Earth & Environment, Pasek explored how high-energy occurrences like lightning can trigger unusual chemical reactions that, in this case, produce an unknown material that is transitional between minerals found on Earth and in space.
Pasek added, “When lightning strikes a tree, the ground typically explodes out and the surrounding grass dies, forming a scar and sending electric discharge through nearby rock, soil, and sand, forming fulgurites, also known as ‘fossilized lightning’.”
The New Port Richey homeowners discovered a fulgurite when they looked for the “lightning scar” and chose to sell it because they thought it was valuable. It was bought by Pasek, who then started working with Luca Bindi, a professor of mineralogy and crystallography at the University of Florence in Italy.
Together, the team set out to investigate unusual minerals that bear the element phosphorus, especially those formed by lightning, to better understand high-energy phenomena.
“It is 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. Florida is the lightning capital of the world and lightning safety is important—if lightning is strong enough to melt rock, it can certainly melt people too,” Pasek stated.
According to Pasek, iron will often accumulate and encrust tree roots in moist conditions like those found in Florida. In this instance, the lightning strike not only set the iron on the tree roots on fire but also ignited the already present carbon in the tree. The interaction of the two elements resulted in the formation of fulgurite, which had the appearance of a metal “glob.”
A previously unidentified material was exposed inside the fulgurite as a colorful, crystal-like matter.
Tian Feng, a co-principal investigator and a USF geology program graduate, tried to recreate the material in a lab. The failed experiment suggests that the material develops swiftly under specific circumstances and that, if heated over an extended period of time, it will change into the mineral found in meteorites.
Previous researchers indicate that lightning reduction of phosphate to have been a widespread phenomenon on the early Earth. However, there is an environmental phosphite reservoir issue in Earth that these solid phosphite materials are hard to restore.
Tian Feng, Study Co-Principal Investigator and Graduate Student, University of South Florida
According to Feng, this discovery could indicate that other reduced mineral forms are possible and that many of them might have been crucial to the emergence of life on Earth.
Pasek asserts that given the scarcity of its natural occurrence, it is uncertain that this material could be mined for applications similar to other phosphates, such as fertilizer. However, Pasek and Bindi intend to conduct more research on the material to see whether it can be formally classified as a mineral and raise more awareness among scientists.
Bindi, L., et al. (2023) Routes to reduction of phosphate by high-energy events. Communications Earth & Environment. doi:10.1038/s43247-023-00736-2