Home›Rocks and Minerals›Minerals›Use›Ore or Metal ExtractionBrowse ByOre or Metal ExtractionOre or Metal ExtractionComments (0)Reader Challenges (0)Ore or Metal ExtractionFilter Results3 entriesStrunz ClassAllOxides and Hydroxides (1)Crystal SystemAllCubic Crystal System (2)Trigonal Crystal System (1)HardnessAll5.75 to 6.25 Mohs (1)LustreAllMetallic (1)ColourAllGrey or Black (1)RarityAllCommon (1)Formed By (Process)AllFractional Crystallization (2)Hydrothermal Circulation (1)Hydrothermal Mineral Deposition (1)Sedimentation (1)Serpentinization (1)Volcanism (1)Weathering (1)Show ResultsBrowseCompareSelect all 3FluoriteOre or Metal ExtractionHematiteOre or Metal ExtractionMagnetiteOre or Metal ExtractionComments (0)No comments yet. Be the first to share a thought.Sign in to join the discussion.Reader Challenges (0)No disputes yet. Spotted an error or a better source? Open the first one.Sign in to dispute this or suggest a correction.