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![Deep-sea mineral deposits as a future source of critical metals, and environmental issues - a brief review](https://image.oaes.cc/0c2e2f0b-ca44-4606-b40d-143a43541854/5691.fig.1.jpg)
Figure 1. Deep-sea minerals: (A) manganese nodules; (B) ferromanganese crust; (C) a massive sulfide formation at hydrothermal vent site; (D) REE-rich marine mud; and (E) phosphorite is a sedimentary rock, defined as a chemical sediment of marine origin.