Organic (Geological Interest)

Mica Schist with Quartz

Muscovite/Biotite Schist

Slickenside in Limestone

Tectonized Limestone / Calcite (CaCO3)

Schist (Graphite or Mica rich)

Crystalline Schist (often containing Muscovite, Biotite, or Graphite)

Milky quartz in host rock

Quartz (SiO₂), likely a quartz vein or quartz-rich fragment

Quartz / Quartzite

Silicon Dioxide (SiO2)

Layered sandstone and shale outcrop

Clastic sedimentary strata, likely sandstone interbedded with mudstone/shale

Iron-rich concretion or ironstone nodule

Likely goethite- and/or hematite-cemented ironstone; exact identification requires testing

Quartzite with Chlorite/Epidote

Metamorphosed Quartzite (SiO2)

Red Quartzite / Ferruginous Sandstone

Quartzite (SiO2 with iron oxide impurities)

Multi-gemstone Quartz and Fluorite Bracelet

Silicon Dioxide (SiO2) and Calcium Fluoride (CaF2)

Weathered rock fragment (likely granite or quartz-rich sandstone)

Uncertain; possible granitic fragment containing quartz and feldspar

Likely weathered quartz-rich rock fragment

Indeterminate; possibly quartz-bearing sandstone or chert with iron-oxide staining

Fossilized shell fragment

Likely a fossil mollusk shell; exact taxon cannot be determined from the image

Limonite

FeO(OH)•nH2O

Graphitic schist

Graphite-rich pelitic schist; primarily quartz, mica, and graphite

Epidote

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

Bog Iron (Limonite Concretion)

Limonite (FeO(OH)·nH2O)

Limonite / Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O)

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

Silicon Dioxide (SiO2) in Host Rock Matrix

Sandstone (Ferruginous)

Arenite with Iron Oxide (Limonite/Hematite) coating

Porphyritic Andesite or Dacite (tumbled pebble)

Porphyritic Igneous Rock (likely Andesite or Dacite)

Ferruginous Quartzite (also known as Ironstone or Gossan)

Ferruginous Quartzite with Goethite/Hematite staining

Quartz-veined dark metamorphic rock, likely schist or gneiss

Quartz-bearing mica schist/gneiss; mainly quartz (SiO₂), feldspar, mica, and iron-oxide staining

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)

Polished fossiliferous limestone (likely crinoidal or coral limestone)

Bioclastic carbonate rock, chiefly calcite (CaCO₃)

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

Sandstone with Quartz Veining

Arenite with SiO2 veins

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz Vein in Greenstone

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

Milky quartz in iron-stained host rock

Quartz (SiO₂), likely with iron-oxide staining; host rock is uncertain from the photo

Weathered quartz- or feldspar-rich rock fragment

Indeterminate light-colored silicate rock; possibly quartz or feldspar in a granitic fragment

Smoky Quartz and Biotite Schist

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

Tumbled brown translucent mineral fragment

Indeterminate; possibly quartz/chalcedony or weathered feldspar

Garnet Gneiss

Garnetiferous quartzo-feldspathic gneiss

Chert

Silicon dioxide (SiO2)

Red Sandstone

Arenite (Iron-rich)