Organic (Geological Interest)

Quartzite with Quartz Veining

Quartzite (primarily SiO2)

Basalt with Weathered Crust

Aphanitic Mafic Igneous Rock (Basalt)

Coquina

Biogenic Limestone

Quartzite (Quartz-rich Cobble)

Quartzite (SiO2)

Chert (with Quartz veins)

Chert (Microcrystalline Silica, SiO2)

Volcanic Tuff (Breccia)

Pyroclastic Tuffaceous Rock

Limestone with Calcite Crust

Sedimentary Calcium Carbonate (CaCO3)

Limonitic Sandstone with Inclusion

Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)

Biotite Schist

Biotite Gneiss/Schist (approximate formula K(Mg,Fe)3AlSi3O10(OH)2)

Limonite

FeO(OH)•nH2O

Greenstone / Basalt

Aphanitic Mafic Igneous Rock (likely altered Basalt)

Ferruginous Sandstone

Clastic Sedimentary Rock (Iron-rich)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert / Flint

Chert (Microcrystalline Quartz, SiO2)

Limonite (Ironstone)

Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)

Sandstone with Manganese Oxide Patina

Clastic Sedimentary Rock (primarily SiO2)

Limonite (Iron Stone Concretion)

Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O

Ferruginous Siltstone or Mudstone

Ferruginous Siltstone / Goethitic Sandstone

Shatter Cone

Impactite (Shatter Cone texture)

Ironstone Concretion / Limonite

Goethite and Limonite (FeO(OH)·nH2O)

Gold in Quartz Ore

Hydrothermal Quartz with native Gold (Au)

Multi-gemstone Quartz and Fluorite Bracelet

Silicon Dioxide (SiO2) and Calcium Fluoride (CaF2)

Graywacke

Argillaceous sandstone

Gossan

Iron-rich regolith (mainly Limonite and Goethite, FeO(OH)·nH2O)

Greywacke with Quartz Veins

Lithic Wacke (SiO2 enriched)

Quartz-veined Metamorphic Rock

Quartz Vein in Phyllite or Schist (SiO2 in Silicate Matrix)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)

Quartz Vein in Greenstone

Hydrothermal Quartz (SiO2) with Chlorite/Epidote Schist host rock

Quartz / Quartzite

Silicon Dioxide (SiO2)

Sandstone with Quartz Veining

Arenite with SiO2 veins

Garnet Gneiss

Garnetiferous quartzo-feldspathic gneiss

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

Limonite / Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O)

Quartz Vein in Matrix (Breccia / Host Rock with Quartz)

Silicon Dioxide (SiO2) in Host Rock Matrix

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Bog Iron (Limonite Concretion)

Limonite (FeO(OH)·nH2O)

Sandstone (Ferruginous)

Arenite with Iron Oxide (Limonite/Hematite) coating

Red Quartzite / Ferruginous Sandstone

Quartzite (SiO2 with iron oxide impurities)

Quartzite with Chlorite/Epidote

Metamorphosed Quartzite (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Red Sandstone

Arenite (Iron-rich)

Smoky Quartz and Biotite Schist

Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)