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Ultra-Pure Quantum Crystals from an Abandoned Mine in the Atacama Desert

Aaron Breidenbach

17 min read·<br>Jan 8, 2026

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A Two Part Post on the Immense Promise and Ecological Tragedy of Natural Herbertsmithite Crystals<br>Introduction<br>Hello Everyone, My name is Dr. Aaron Breidenbach. For those who haven’t been following my journey, I grew crystals of Zn-Barlowite and Herbertsmithite in my PhD at Stanford. These crystals are candidates to be a new novel state of matter called a “quantum spin liquid” (QSL). I just published a paper in nature physics (free version here) with Young Lee’s Lab, providing the strongest evidence to date for the presence of this mythical magnetic state in these crystals. Due to these properties, Zn-Barlowite and its sister QSL candidate material Herbertsmithite have immense potential to be used in future large scale quantum computers. Given what LLMs are currently doing on silicon, one can only imagine how society-altering these crystals might be one day if we can actually fashion them productively in a quantum computer.<br>What’s more amazing to me about these crystals is that they grow in nature as well. I will emphasize that this is an absolute anomaly. To the best of my knowledge, this is the only crystal with any bulk quantum properties that grows in nature (other than its sister materials like Atacamite). Quantum physics is hard, and me and all of my colleagues in condensed matter physics spend hours intentionally mixing very specific ratios of strange elements to make synthetic quantum crystals like superconductors. This is the norm. And yet, somehow, these crystals, among the most mysterious of them all, just grow naturally, and they have probably been sitting around in the earth’s crust for millions of years or more, long before the dawn of apes as a species.<br>With this mystical mystery as motivation, I recently set off on an adventure to the Atacama Desert in Chile to find these crystals in their natural habitat. What I found astounded me for many reasons. This is a two part post. In the first post here, I will focus on the immense potential that natural crystals have for advancing our knowledge of quantum physics. Then, in the second post, I will focus on how these crystals are tragically being destroyed in large scale ecologically damaging mining practices in the Atacama Desert.<br>(For other content related to this project, including interviews, videos, and published papers, please see my website, thequantumarcheologist.org)<br>The Discovery and the Promise<br>Press enter or click to view image in full size

A photo of all of the Herbertsmithite crystals I found in a single boulder in an abandoned mine in the Atacama Desert. While I have yet to separate these crystals, I estimate that I have at least twice the mass of Herbertsmithite crystals from this one discovery as compared to what I grew in 6 years as a graduate student at Stanford.Press enter or click to view image in full size

A close-up image on one of the higher-quality Herbertsmithite crystal formationsIn my journey to Chile I was successful in finding the legendary natural Herbertsmithite crystals. I made this discovery in collaboration with Anthropologist Vicente Carrasola Vega from the University of Chile. He is the one that spotted the crystals in the field, and he proved to be an indispensable guide, translator, and knowledge holder in the desert. Amazingly, we found these crystals in the waste tailings of the abandoned San Francisco mine. We then verified the identity of these crystals with x-ray scattering with the help of Professor Joseline Tapia and staff in the geology department at the Universidad Católica del Norte in Antofagasta Chile.<br>Press enter or click to view image in full size

Powdered X-ray spectra of the crystals I found, confirming its identity as Herbertsmithite mixed with AtacamiteThis was no small discovery either. We found a lot of these crystals. I have yet to separate and measure all of these crystals, but I’m conservatively estimating by eye that we have at least 10 grams of hexagonal green crystals (but probably much more). I’m hoping most of this is Herbertsmithite, and we also have at least a few grams of the related minerals Atacamite and Zn-Paratacamite. (The x-ray scattering suggests these crystals are mostly Herbertsmithite, ~65% by composition, but this is unreliable and limited to one sample. Future measurements will be more accurate in pinning down an exact ratio and amount).<br>For comparison, the lab grown crystals are very difficult to grow. It takes about a full work week of preparation and 9 full months of waiting for them to grow to full size. This process also involves a lot of training to master. It is additionally very expensive in terms of equipment overhead (>$10,000) and the...