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Keeping science accessible. Researching how minerals can be used to solve problems like climate change, pollution, and disease. @ NHMLA, USC, NASA-JPL
Apatite, Natural History Museum of Los Angele, photo by Stan Celestian.

Rare earth elements (REEs) are a group of similar chemical elements that have become an important research area in the mineral and materials sciences communities due to their potential use in energy generation and storage, for a greener Earth. The element neodymium (Nd) makes very powerful magnets, lanthanum (La) and cerium (Ce) are used for petroleum catalytic conversion and air pollution controls, gadolinium (Gd) and europium (Eu) are used as phosphors in lasers/digital screens/medical imaging, and all the above, plus lutecium (Lu) and samarium (Sm), are used in smart missiles, guidance systems, communication systems, and many other applications. To list…


Standing wave (black) and oscillation nodes (red dots).

To analyze a crystallization event in a liquid, you typically have to put the crystal on (or in) something. Most of the time that isn’t a problem, but what if you were required to look at the shape of the droplet? Or a live bug that you don’t want crawling away? The water droplet changes shape as soon as it touches a glass microscope slide, and the bug will escape unless you pin it down and kill it. In general, I am referring to challenges associated with a sample holder impacting a signal or the ability to measure a signal.


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

When you squeeze something, it should get smaller — that’s just common sense. You squeeze a sponge to make it smaller, so that water gets pushed out. But why doesn’t the water compress along with the sponge as you squeeze it? Why doesn’t the water stay in the sponge, but instead drips all over the place? It turns out that water is nearly incompressible. Even though water is trapped in the sponge, it doesn’t compress at the same rate, so the water has nowhere to go except out. Even at the bottom of the ocean, water basically has the same…


Nearly a mile underground in the Northeast part of England, there are crystals and life, so that’s where I went.

Steel beams support the mine walls along a salt road 1.1 km below the surface of the Earth.

I was part of a NASA Jet Propulsion Lab team to go deep underground in search of bacteria, and if found, determine if they are alive or dead. If they are viable, then what is the mineral-microbe interaction? What role do minerals have in life preservation? Also, from where did these halobacteria come? Were they part of the original salt rocks, did they come from somewhere else, did humans bring them from the surface? Lots and lots of questions that…


Getting your research published in a “peer-reviewed” scientific journal is still the gold standard for acceptance by the broader scientific community — despite its many problems — and I’m guilty of following this model, sorry. There are currently over 28,000 active scientific journals, some are good, and some are predatory. The white noise of millions of papers published per year makes it very hard to find relevant and reliable science. In a sense, it is probably more challenging to get interesting science visible to the broader community now (and finding other people’s work), than it was three-hundred years ago.

The…


Ooids from Cat Bay, Bahamas.

Have you ever watched a bug or a lizard on a cold morning? They remain motionless until the sun warms them. You can pick it up, and it won’t do anything to escape. The viral videos of a Florida iguana on a winter cold-snap is a great example. That’s what it means to be cold-blooded; cold-blooded animals do not generate their own heat, unlike us warm-blooded humans.

Most, but not all, modern reptiles are strictly cold-blooded, and for a long time, it was believed that dinosaurs were as well. Now some fossil evidence suggests that dinosaurs may have been able…


A museum mineral collection is a vast repository of Earth and planetary materials. It is a resource for researchers looking to gain access to the rarest minerals and gems, and those that are looking for intricate details in species variation. Some researchers need access to common minerals, but don’t have the means to acquire specimens themselves. More importantly, in my opinion, a museum mineral collection can be used to inspire wonder to our visitors, inform the public of current issues in a safe and comfortable space, shape their world view if they trust us, or just allow them to appreciate…


Toxic and radioactive metals left over from the nuclear fuel cycle are of primary concern to the health of humans and the environment. Why? Because as the uranium from the reactor core ‘burns’, it decays to other elements, and leaving a pile of toxic material. Most of these remaining elements are still radioactive, and of particular concern are cesium (Cs) and strontium (Sr), which have the highest level of radioactivity in the waste.


Climate change has many impacts on our planet. Some of the ones you might hear about in the news include sea-level rise caused by melting ice and ocean heating, increases in wildfires because of long-term droughts, changes in extreme weather events due to variations in atmospheric heating, and acidification of the oceans as they absorb carbon dioxide from the atmosphere. Here I will discuss some of the mineral science research that I’m doing with other scientists, and follow that up with a more general discussion of ocean acidification.

Mineral stability in today’s changing ocean

Water, living organisms, and minerals formed organically by living things and…


Crystals are fun and easy to grow, and it’s a great introduction to the sciences. Anyone can grow beautiful crystals, you just need a little bit of time and a couple of ingredients. I decided to write this post because my son’s teacher wanted to add some crystal growing experiments to her class. There are tons of examples online, but I wanted to add my own personal touch.

There are only a few steps involved in crystal growing, and the procedures are nearly identical for all the different types of crystals described below. All the crystallization experiments described here form…

Aaron Celestian, Ph.D.

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