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The metal-insulator transition driven by electronic correlations is one of the most fundamental concepts in condensed matter. In mixed-valence compounds, this transition is often accompanied by charge ordering (CO), resulting in the emergence of complex phases and unusual behaviors. The famous example is the archetypal mixed-valence mineral magnetite, Fe3O4, exhibiting a complex charge-ordering below the Verwey transition, whose nature has been a subject of long-time debates. In our study, using high-resolution X-ray diffraction supplemented by resistance measurements and DFT+DMFT calculations, the electronic, magnetic, and structural properties of recently synthesized mixed-valence Fe4O5are investigated under pressure to ∼100 GPa. Our calculations, consistent with experiment, reveal that at ambient conditions Fe4O5is a narrow-gap insulator characterized by the original Verwey-type CO. Under pressure Fe4O5undergoes a series of electronic and magnetic-state transitions with an unusual compressional behavior above ∼50 GPa. A site-dependent collapse of local magnetic moments is followed by the site-selective insulator-to-metal transition at ∼84 GPa, occurring at the octahedral Fe sites. This phase transition is accompanied by a 2+ to 3+ valence change of the prismatic Fe ions and collapse of CO. We provide a microscopic explanation of the complex charge ordering in Fe4O5which "unifies" it with the behavior of two archetypal examples of charge- or bond-ordered materials, magnetite and rare-earth nickelates (RNiO3). We find that at low temperatures the Verwey-type CO competes with the "trimeron"/"dimeron" charge ordered states, allowing for pressure/temperature tuning of charge ordering. Summing up the available data, we present the pressure-temperature phase diagram of Fe4O5 © 2022 American Chemical Society. All rights reserved. EAR-1634415; National Science Foundation, NSF: EAR-1606856; U.S. Department of Energy, USDOE: DE-FG02-94ER14466; Office of Science, SC; Argonne National Laboratory, ANL: DE-AC02-06CH11357; Deutsche Forschungsgemeinschaft, DFG: OV-110/3-2; Russian Foundation for Basic Research, РФФИ: 20-42-660027; Israel Science Foundation, ISF: 1552/18, 1748/20; Russian Science Foundation, RSF: 19-72-30043; 122021000039-4 We thank L. S. Dubrovinsky, I. A. Abrikosov, and V. Prakapenka for their interest in this research and B. Lavina for fruitful discussions about in situ DAC synthesis. We are grateful to M. Hanfland for the assistance in using beamline ID-15B of ESRF, Grenoble, France. Portions of this work were performed at GeoSoilEnviroCARS (The University of Chicago, Sector 13), Advanced Photon Source (APS), Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (Grant EAR-1634415) and Department of Energy-GeoSciences (Grant DE-FG02-94ER14466). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Use of the COMPRES-GSECARS gas loading system was supported by COMPRES under NSF Cooperative Agreement EAR-1606856 and by GSECARS through NSF Grant EAR-1634415 and DOE Grant DE-FG02-94ER14466. The work was partly supported by the Israel Science Foundation (Grants No. 1552/18 and 1748/20) and the Deutsche Forschungsgemeinschaft Grant No. OV-110/3-2. The theoretical analysis was supported by Russian Foundation for the Basic Research (Project No. 20-42-660027). The DFT calculations were supported by the state assignment of Minobrnauki of Russia (Theme “Electron” No. 122021000039-4). The DFT+DMFT calculations were supported by the Russian Science Foundation (Project No. 19-72-30043).