Mineral, Specifically An Iron Ore

Iron-rich jasper or weathered hematite fragment

Hematite (Fe₂O₃) in microcrystalline quartz/jasper matrix

Hematite

Iron(III) oxide (Fe2O3)

Ironstone Concretion / Limonite Specimen

Goethite and Limonite (Hydrous Iron Oxides)

Olivine (Peridot in gem form)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Specular Hematite

Hematite (Fe2O3)

Weathered iron-rich concretion or lateritic pebble

Goethite/hematite-bearing ferruginous concretion; composition uncertain from image

Pink Himalayan Salt (Halite)

Halite - NaCl (Sodium Chloride) with trace Iron Oxide and Magnesium

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides (goethite)

Magnetite (potentially Hematite)

Magnetite (Fe₃O₄)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite (Fe2O3) or Limonite (FeO(OH) nH2O)

Hematite

Iron(III) oxide (Fe2O3)

Orange Calcite

Calcium Carbonate (CaCO3)

Probable iron-rich mineral or weathered rock fragment

Indeterminate; possibly limonite/goethite-bearing material

Specular Hematite (on Schist/Matrix)

Hematite (Alpha-Fe2O3)

Amethyst on Matrix

Amethyst (Silicon Dioxide, SiO2) with impurities of iron and irradiation

Ironstone Concretion

Siderite or Hematite Concretion

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Banded Iron Formation (BIF)

Banded Iron Formation

Milky Quartz

Silicon Dioxide (SiO2)

Specular Hematite with Quartz

Ferric oxide (Fe2O3) and Silicon dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) - Impure Cryptocrystalline Quartz

Weathered iron-rich rock fragment

Likely limonite/goethite-bearing material; exact identification requires testing

Botryoidal hematite (iron-oxide specimen)

Hematite, Fe₂O₃; possibly mixed with goethite/limonite

Limonite (Yellow Ochre)

Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)

Polished Hematite Tower

Hematite (Fe2O3)

Ironstone / limonite-rich rock

Limonite, chiefly hydrated iron oxides (FeO(OH)·nH₂O), commonly mixed with goethite and hematite

Likely ironstone pebble

Iron-oxide-rich concretion, composed mainly of goethite and/or hematite

Jasper (specifically Red Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Pyrite in Matrix (often with Chalcopyrite)

Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)

Iron Ore (Hematite/Goethite)

Ironstone (Fe2O3 / FeO(OH))

Hematite

Iron Oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Hematite

Hematite (Fe2O3)

Weathered iron-rich rock, possibly laterite or limonite-bearing quartzite

Limonite/goethite mixture, commonly FeO(OH)·nH₂O, with possible quartz and iron oxides

Amethyst Lace Agate / Banded Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

Iron-oxide-stained rock, likely limonite/goethite-rich material

Likely goethite (α-FeO(OH)) and/or limonite (a mixture of hydrated iron oxides), staining a silicate-rich rock

Tiger's Eye (with Hematite/Magnetite matrix)

Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH/Fe2O3)

Pyrite (or Arsenopyrite / Ore mineral aggregate)

FeS2 (Iron Sulfide)