After a mere two centuries of trying, scientists have finally managed to grow the mineral dolomite in a lab, cracking the long-standing geological enigma known as the "Dolomite Problem." Researchers from the University of Michigan and Hokkaido University in Sapporo, Japan, succeeded by developing a new theory based on detailed atomic simulations.
Dolomite is a widespread mineral found in iconic locations like the Dolomite mountains in Italy, Niagara Falls, and Utah's Hoodoos. It's abundant in rocks older than 100 million years but is rarely seen forming in more recent environments, which has been a source of scientific head-scratching for generations.
The key breakthrough was understanding what disrupts dolomite as it forms. Its structure is made of alternating layers of calcium and magnesium, but these elements often attach randomly during growth, creating structural defects that block further progress. At that flawed rate, forming a single well-ordered layer could take up to 10 million years.
The researchers realized these defects aren't permanent. Atoms out of place are less stable and more likely to dissolve when exposed to water. In nature, cycles like rainfall or tidal changes repeatedly wash away these flawed areas. Over time, this clears the surface so new, properly arranged layers can form, allowing dolomite to build up over geological periods instead of geological eternities.
To test this, the team needed to model atomic interactions, a task usually demanding immense computing power. Researchers at U-M's Predictive Structure Materials Science (PRISMS) Center developed software that simplified the challenge. "Each atomic step would normally take over 5,000 CPU hours on a supercomputer. Now, we can do the same calculation in 2 milliseconds on a desktop," said Joonsoo Kim, the study's first author.
For experimental evidence, Yuki Kimura and Tomoya Yamazaki at Hokkaido University used a transmission electron microscope in an unconventional way. They pulsed its electron beam 4,000 times over two hours on a small crystal in a solution, using the beam's ability to split water and create acid to dissolve defects as they formed. The crystal grew to about 100 nanometers, representing around 300 layers of dolomite - a far cry from the previous record of five.
Solving this ancient mystery has modern implications. "Our theory shows that you can grow defect-free materials quickly, if you periodically dissolve the defects away during growth," said Wenhao Sun, the corresponding author. This insight could improve the production of semiconductors, solar panels, batteries, and other technologies. The research was funded by the American Chemical Society PRF New Doctoral Investigator grant, the U.S. Department of Energy, and the Japanese Society for the Promotion of Science.