Sedimentary Or Metamorphic (Low Grade)

Ferruginous Sandstone

Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)

Ferruginous Sandstone (Gozzan-like)

Ferruginous Sandstone (SiO2 with FeO(OH) inclusions)

Ironstone Nodule (Ironstone Concretion)

Siderite-rich Mudstone (FeCO3) or Limonite (FeO(OH)·nH2O)

Iron Gossan (Limonite/Goethite)

Hydrated Iron Oxides (FeO(OH)·nH2O) from oxidation zones

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Almandine Garnet in Schist

Almandine, Fe3Al2(SiO4)3

Mica Schist

Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)

Pyrite

Iron Disulfide (FeS2)

Greenschist

Chlorite schist

Blue Apatite

Apatite (Ca5(PO4)3(F,Cl,OH))

Industrial Diamond (Bort or Boart)

Diamond (pure Carbon, C)

Chert (Common Opal variant)

Silicon Dioxide (SiO2)

Ferruginous Conglomerate

Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))

Ironstone (likely Ferruginous Siltstone/Sandstone)

Ferruginous sedimentary rock (FeOx-rich clastic)

Ironstone Concretion

Siderite or Hematite-bonded Concretion

Ironstone Concretion (Iron-rich Mudstone)

Siderite / Geothite concretion (FeCO3 / FeO(OH))

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)

Gneiss (specifically Micaceous Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Milky Quartz

Silicon Dioxide (SiO2)

Biotite Gneiss

Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)

Gneiss (Granitic Gneiss)

Gneiss

Red Jasper

Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)

Gneiss (with Mica and Quartz)

Gneissic Metamorphic Rock

Pyrite

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Celestite (Celestine)

Celestine (Strontium Sulfate, SrSO4)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Gneiss (Granitic Gneiss)

Gneiss

Schist

Schist (metamorphic rock)

Gneiss

High-grade metamorphic rock (Gneiss)

Fuchsite Schist

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist

Mica Schist

Crystalline Schist (often containing Muscovite, Biotite, and Quartz)

Serpentine

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

Vesicular Basalt with Opal or Quartz

Vesicular Basalt (Amorphous SiO2.nH2O if Opal)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss

Gneiss (high-grade metamorphic rock)