How a mineral gets bigger when squeezed

and what it could tell us planetary processes in our solar system

Looking deep into Earth, Mars, and Moon. The types of minerals we might find on Mars, Ceres, and icy moons could give us clues about their past and current geological processes. Minerals are often used as a way of reconstructing past environments, because they can change depending on how the environment changes, including what life had done. And when the environment changes, the minerals are usually the only things robust enough to record what had happened. However, in order for geologists to be able to interpret the past events on places other than Earth, we need to know the geological conditions that led to mineral formation under a huge range of conditions. Image
Nice nacrite crystals (white) are difficult to find, and when you do, they are often very small. This one is only a few millimeters in size. Mineral specimen from the Natural Hisotry Museum of Los Angeles County. Sample locality: Mt. St. Hilaire, Quebec, Canada.
A layer of H2O (hydrogen atoms removed for clarity) molecules in an ice-like hexagonal bonding gemoetry found inside nacrite (left) next to a layer of ice as normal crystalline ice we find in snow (also called ice-VI). Notice the similarities in the atomic arrangement. The nacrite ice-like layer isn’t perfectly hexagonal like crystalline ice, but it’s really close!
My simplified version of a graph from the Hwang et al. (2020) paper. Pressure is on the X-axis, and volume change is on the Y-axis. As you can see, when the experiment started, the volume of nacrite decreased a little, but when the sample got to 1.8 GPa, the volume suddenly increased.

Keeping science accessible. Researching how minerals can be used to solve problems like climate change, pollution, and disease. @ NHMLA, USC, NASA-JPL