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	<title>high-pressure mineral phase transitions &#8211; Science</title>
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	<title>high-pressure mineral phase transitions &#8211; Science</title>
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		<title>Scientists directly observe shock-formed davemaoite, a deep-Earth calcium perovskite</title>
		<link>https://scienmag.com/scientists-directly-observe-shock-formed-davemaoite-a-deep-earth-calcium-perovskite/</link>
		
		<dc:creator><![CDATA[Violet Maxwell]]></dc:creator>
		<pubDate>Fri, 04 Sep 2026 13:48:42 +0000</pubDate>
				<category><![CDATA[Earth Science]]></category>
		<category><![CDATA[calcium silicate perovskite]]></category>
		<category><![CDATA[calcium silicate perovskite in Earth's mantle]]></category>
		<category><![CDATA[davemaoite discovery and characterization]]></category>
		<category><![CDATA[Deep Earth geophysics]]></category>
		<category><![CDATA[deep planetary interiors]]></category>
		<category><![CDATA[Deep-Earth mineral formation]]></category>
		<category><![CDATA[Deep-Earth minerals]]></category>
		<category><![CDATA[diamond inclusions as mineral records]]></category>
		<category><![CDATA[dynamic compression experiments]]></category>
		<category><![CDATA[Earth's lower mantle chemistry]]></category>
		<category><![CDATA[geophysical experiments in mineral physics]]></category>
		<category><![CDATA[high-pressure mineral crystallization]]></category>
		<category><![CDATA[high-pressure mineral phase transitions]]></category>
		<category><![CDATA[high-pressure mineral synthesis]]></category>
		<category><![CDATA[impact of dynamic compression on deep minerals]]></category>
		<category><![CDATA[impact-induced mineral transformations]]></category>
		<category><![CDATA[implications for rocky planet interiors]]></category>
		<category><![CDATA[lowermost mantle mineralogy]]></category>
		<category><![CDATA[mineral formation under extreme conditions]]></category>
		<category><![CDATA[mineral inclusions in diamonds]]></category>
		<category><![CDATA[shock-formation of davemaoite]]></category>
		<category><![CDATA[shock-induced mineral crystallization]]></category>
		<guid isPermaLink="false">https://scienmag.com/scientists-directly-observe-shock-formed-davemaoite-a-deep-earth-calcium-perovskite/</guid>

					<description><![CDATA[In a landmark experiment that peers into the violent birth of one of Earth&#8217;s deepest minerals, researchers have directly observed, for the first time, the shock-induced formation of davemaoite — the calcium-rich silicate perovskite that dominates the chemistry of the lowermost mantle. The finding, published in Nature Communications, resolves a decades-old question about whether the [&#8230;]]]></description>
										<content:encoded><![CDATA[<p>In a landmark experiment that peers into the violent birth of one of Earth&#8217;s deepest minerals, researchers have directly observed, for the first time, the shock-induced formation of davemaoite — the calcium-rich silicate perovskite that dominates the chemistry of the lowermost mantle. The finding, published in Nature Communications, resolves a decades-old question about whether the high-pressure calcium silicate perovskite phase can crystallize from dynamic compression on nanosecond timescales, and it carries sweeping implications for how scientists interpret the mineral makeup of the deep Earth and the interiors of rocky planets beyond our own.</p>
<p>Davemaoite is no ordinary mineral. Synthesized only in trace quantities in the laboratory and preserved in nature exclusively as microscopic inclusions trapped within diamonds sourced from hundreds of kilometers below the surface, it was formally recognized by the International Mineralogical Association in 2021 and named in honor of geophysicist Ho-kwang &#8220;Dave&#8221; Mao, a pioneer of high-pressure research. Chemically, davemaoite is calcium silicate in the perovskite structure, CaSiO₃, and beneath roughly 500 to 600 kilometers depth — the pressures at which it becomes stable — it acts as the principal reservoir for calcium in the lower mantle. Equally important, its crystal lattice tolerates a remarkable range of substitution: radioactive isotopes such as thorium and uranium, heat-producing potassium, and rare-earth elements all preferentially partition into davemaoite, making this single phase a dominant control on the thermal and chemical evolution of the planet&#8217;s interior.</p>
<p>The stability of davemaoite under equilibrium conditions has been well charted using laser-heated diamond anvil cells, devices that squeeze samples between gem-quality diamonds while laser beams raise temperatures to thousands of degrees. But equilibrium experiments answer only part of the question. Much of the extreme pressure-temperature history experienced by planetary materials — hypervelocity impacts, accretionary collisions, shock metamorphism in meteorite parent bodies — unfolds on microsecond or nanosecond timescales, far too brief for conventional thermodynamic reasoning to confidently apply. Whether calcium silicate perovskite forms at all during such violent, rapid compression, or whether the material instead remains trapped in metastable states, has remained experimentally inaccessible. Dynamic compression experiments had probed the behavior of CaSiO₃ glass and other precursors, but the direct, in situ observation of the crystalline davemaoite phase nucleating under shock had never been achieved.</p>
<p>The research team, led by M. Lee, S. Takagi, and M. Jang along with colleagues, closed that gap by coupling gas-gun or laser-driven shock compression with fast, time-resolved X-ray diffraction at a synchrotron facility. In this class of experiment, a precisely shaped projectile or intense laser pulse strikes a target assembly containing the calcium silicate sample, launching a planar shock wave through it. As the shock front sweeps across the sample, the material is compressed to pressures of tens to well over a hundred gigapascals — millions of times atmospheric pressure — and heated substantially by the work of compression itself, all within a few nanoseconds. During an infinitesimally short window in which the sample resides in the shocked state, an ultrafast X-ray pulse scatters off the atomic lattice, and the resulting diffraction pattern, recorded with a high-speed detector, reveals whether the atoms have reorganized into a new crystal structure.</p>
<p>When the researchers examined the diffraction records from their shock experiments, the signature was unmistakable. Distinct diffraction peaks appeared at angles and with systematic intensity distributions matching the cubic perovskite structure of davemaoite, demonstrating that the phase had not merely survived the shock but had actively formed, nucleating and growing from the starting material within the nanosecond-scale lifetime of the shocked state. The measured lattice parameters of the shock-produced phase varied systematically with the pressure of each shot, tracing an equation-of-state consistent with, and extending, the previously measured compression behavior of davemaoite from static experiments. The clarity of the observation rules out alternative interpretations in which the diffraction signal could be attributed to untransformed precursor phases or to mixed high-pressure assemblages.</p>
<p>The speed of the transformation is the scientifically startling element. Crystallographic phase transformations require atoms to break bonds, migrate, and reorder; in conventional metallurgy and mineral physics, such reconstructions are often assumed to stall when the available time drops below the scale of atomic diffusion. Yet davemaoite formation under shock apparently proceeds by a mechanism that circumvents slow, diffusive transport. The extreme temperatures generated by shock heating — potentially several thousand kelvin at the highest pressures achieved — together with the enormous driving force for the transition deep inside its stability field, likely enable a martensitic-like, diffusionless, or very rapid reconstructive pathway. Alternatively, pre-existing structural motifs in the calcium silicate starting material may act as nuclei that rapidly reorganize into the perovskite framework. Distinguishing among these mechanisms will be a focus of follow-up work, but the essential fact stands: nature can build this deep-mantle mineral on timescales nine orders of magnitude shorter than the geological times over which it normally appears.</p>
<p>The confirmation carries immediate consequences for planetary science. Hypervelocity impacts were rampant during the accretion of Earth and the other terrestrial planets, and they remain a fundamental process on planetary surfaces today. Meteorites commonly preserve evidence of shock pressures exceeding 20 gigapascals, and some highly shocked samples, notably the lherzolitic shergottite meteorites from Mars and certain chondrites, have been suggested to contain high-pressure calcium silicate phases. Demonstrating that davemaoite can form directly under shock legitimizes the use of shock-synthesized calcium perovskite as a recorder of ancient impact conditions. The presence of this phase in a meteorite can now be read as a quantitative fingerprint of the peak pressure and temperature the rock endured, sharpening reconstructions of impact histories on Mars, the Moon, and asteroidal bodies.</p>
<p>The result also touches one of the most consequential debates in Earth science: the disposition of subducted oceanic crust in the lower mantle. When oceanic plates sink into the mantle, their basaltic and gabbroic components carry calcium and heat-producing elements downward, and at lower-mantle pressures these components reorganize into a mineral assemblage in which davemaoite is a key constituent. Because davemaoite hosts uranium, thorium, and potassium, its abundance and distribution modulate where the mantle&#8217;s internal radiogenic heat is released, feeding back into convection patterns, plume generation, and the long-term cooling of the planet. Knowing that the perovskite structure forms readily — even under conditions far from equilibrium — strengthens confidence in geochemical models that assign davemaoite a major role in the deep carbon, calcium, and heat budgets, and it suggests that impact-processed mantle material in early Earth could have accessed the same mineralogy as slowly equilibrated material.</p>
<p>Technologically, the experiment showcases how far dynamic compression science has advanced. The marriage of high-repetition-rate shock drivers with fourth-generation synchrotron X-ray sources capable of delivering femtosecond to picosecond pulses has opened a new observational regime: in situ crystallography of matter in extreme transient states. Where earlier generations of researchers had to rely on recovering samples after the event — a technique that captures only what survives the journey back to ambient pressure — the modern approach films the transformation as it happens. The davemaoite result demonstrates that even subtle crystallographic distinctions, such as those between cubic and slightly distorted perovskite structures, can now be resolved in shocked minerals, effectively bringing the power of diamond anvil cell crystallography to the nanosecond world of shock physics.</p>
<p>The work resonates far beyond Earth as well. Calcium-bearing silicate perovskites are expected constituents of super-Earths, where greater masses and gravitational compression generate lower-mantle-like conditions at shallower depths and stabilize davemaoite over a far larger fraction of the planet&#8217;s volume. Impact processing is ubiquitous in planetary systems, and the demonstration that the correct mineralogy can arise during shock means that models of exoplanet interiors and their thermal evolution need not assume slow equilibrium to justify the presence of calcium perovskite phases. In this sense, the experiment links the nanosecond physics of a laboratory shock wave to the gigayear evolution of worlds many light-years away.</p>
<p>As with any pioneering measurement, questions remain. The precise pressure range over which shock-induced davemaoite nucleates, the kinetic pathway and its dependence on starting material microstructure, and the partitioning behavior of trace elements during rapid crystallization are all open targets for future experiments. Still, the direct observation reported by Lee, Takagi, Jang, and colleagues marks a genuine first: a mineral that defines the deepest realms of our planet, normally the exclusive province of geologic time and diamond-locked inclusions, captured in the act of being born in a fraction of a billionth of a second. In that fleeting flash of diffraction, the laboratory has reproduced — and seen — one of Earth&#8217;s most elusive building blocks under construction.</p>
<div class="scienmag-article-metadata"><strong>Subject of Research:</strong> Direct in situ observation of the shock-induced formation of davemaoite, the high-pressure calcium silicate perovskite (CaSiO₃) of Earth&#8217;s lower mantle, using time-resolved X-ray diffraction during dynamic compression.</p>
<p><strong>Article Title:</strong> Direct observation of shock-induced formation of davemaoite, Ca-perovskite</p>
<p><strong>Article References:</strong> Lee, M., Takagi, S., Jang, M., Lee, G., Lee, H., Takahashi, N., Choi, J., Lee, Y., Seoung, D., Park, C., Miyanishi, K., Yabuuchi, T., Ozaki, N., Pikuz, T., Nakamura, H., Amouretti, A., Fei, Y., Tracy, S. J., Hwang, H., &amp; Kim, D. (2026). Direct observation of shock-induced formation of davemaoite, Ca-perovskite. <em>Nature Communications</em>. <a href="https://doi.org/10.1038/s41467-026-76624-y" target="_blank" rel="noopener noreferrer">https://doi.org/10.1038/s41467-026-76624-y</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s41467-026-76624-y" target="_blank" rel="noopener noreferrer">10.1038/s41467-026-76624-y</a></p>
<p><strong>Keywords:</strong> davemaoite, calcium silicate perovskite, shock compression, lower mantle, X-ray diffraction, high-pressure mineral physics, dynamic compression, meteorite shock metamorphism, mantle geochemistry, planetary interiors, perovskite structure, deep Earth</p>
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