You are living in an amazing time on planet Earth — mineralogically speaking.
Scientists say there are more unique minerals on our planet than ever before in its 4.5-billion-year history, and it's thanks in part to us.
In a paper published this week in American Mineralogist, a team of researchers argues that human activities have helped create a distinct geological era. They call it the Anthropocene Epoch.
"If you came back to Earth 100 million years from now, you would find a distinctive marking layer of concrete alloys, batteries and myriad crystalline forms that characterize our age and show it is different from anything that has come before," said Robert Hazen, a senior staff scientist at the Carnegie Institution of Science who led the new work.
The official definition of a mineral is a naturally occurring crystal with a unique chemical composition and well-defined structure.
So far, mineralogists have discovered about 5,200 distinct and officially recognized mineral species here on Earth, although experts say there could be as many as 1,500 others out there still to be found.
In the new paper, the researchers catalog 208 mineral and mineral-like compounds that they say occur primarily because of human activity on the planet.
Some of these new crystal structures have been synthesized deliberately — for example in industrial processes like those used to make bricks, porcelain and reinforced concrete.
Others have been forged by accident as a result of mining or the weathering of ancient bronze, lead and tin artifacts.
For example, Abhurite, pictured below, was found at the wreck of the cargo ship Cheerful, now 14 miles off the coast of St. Ives in Cornwall, England.
"Simply put, we live in an era of unparalleled inorganic compound diversification," Hazen said.
And we may still be at the beginning.
"The quantities are only going to grow as more and different kinds of materials are produced and then weathered," he said.
Usually when we talk about how humans are altering the planet it's not a good thing, but Hazen said the new minerals we've helped bring into being are generally benign and some are downright useful.
"The ability of humans to synthesize and manipulate new crystals is a boon to society," he said. "Your laptop is filled with crystals; all the building materials we use in our modern age are made possible by the incredible diversity of natural minerals."
Many of the "human-mediated" minerals described in the paper were discovered on the walls and timbers of abandoned mines. Some were found in ore dumps, others on smelters or on weathered slag — the stony material that is left over after metal has been separated from its raw ore.
New minerals have also been found in prehistoric sacrificial burning sites and on ancient works of art. Mineralogists have even discovered a few types of mineral-like materials that occur exclusively in museums when limestone and fossils interact with chemicals in storage drawers and create what looks like a white crust.
One of Hazen's favorite minerals is tinnunculite, which was discovered in a burning Russian coal mine.
"It's basically the interaction of falcon poop and the hot gases from the mine," Hazen said. However, this mineral was also discovered on Russia's Mt. Rasvumchorr, where it occurred with no human intervention.
Anthony Kampf, curator emeritus of mineral sciences at the Museum of Natural History Los Angeles, discovered more than two dozen of the minerals described in the paper.
Although he wasn't involved in this particular study, he said that the catalog of human-mediated minerals and mineral-like substances is an interesting way of looking at contemporary mineral research.
"The processes that are going on today are not that different from what has been going on for millions of years, but man is having a remarkable impact," he said. "New crystals are resulting from us just being here."
He added that some of these newly discovered, "accidental" minerals are inspiring scientists who work to create new compounds.
"Sometimes the most interesting compounds are those that happen by accident," he said.
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