Sedimentary (Chemically Precipitated) Or Metamorphic

Magnetite

Magnetite (Fe3O4)

Septarian Nodule

Septarian Concretion (Calcite, Aragonite, Limestone)

Jasper with Agate Inclusions

Silicon Dioxide (SiO2) - variety of Quartz/Chert

Blue Calcite

Calcium Carbonate (CaCO3)

Gold-bearing Quartz Vein in Mafic Rock

Hydrothermal Quartz Vein within Greenschist/Amphibolite facies (SiO2 with Au)

Chert / Flint Arrowhead

Microcrystalline Quartz (SiO2)

Quartzite (or Massive Quartz)

Silicon Dioxide (SiO2)

Limestone Pebble

Sedimentary Calcium Carbonate (CaCO3)

Septarian Nodule

Septarian Concretion (Calcite, Aragonite, and Limestone)

Septarian Nodule

Septarian Concretion (Calcite, Aragonite, and Limestone)

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Jasper-Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Limestone

Calcium Carbonate (CaCO3)

Limestone Cobble

Sedimentary Calcium Carbonate (CaCO3)

Quartz

Silicon Dioxide (SiO2)

Almandine Garnet in Schist

Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist

Chert (includes Flint & Jasper)

Chert (Siliceous sedimentary rock, chemical formula SiO2)

Quartz (River Cobble)

Silicon Dioxide (SiO2)

Lichen-covered graywacke or granitic glacial cobble

Indeterminate; likely quartz–feldspar–mica rock, possibly weathered granite or granodiorite

Tumbled honey calcite (likely aragonite/calcite material)

Calcite, CaCO₃; possibly aragonite, a polymorph of CaCO₃

Milky Quartz

Silicon dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Calcite (likely a tumbled specimen)

Calcite (CaCO 3 )

Limestone

Limestone (Calcium Carbonate, CaCO3)

Blue Apatite

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

Quartz Pebble

Silicon Dioxide (SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Banded Limestone

Calcareous sedimentary rock (CaCO3)

Limestone (or Calcite Pebble)

Calcium Carbonate (CaCO3)

Lapis Lazuli

Lapis Lazuli (Complex rock primarily composed of Lazurite (Na,Ca)8[(SO4,S,Cl)2|(AlSiO4)6], Calcite, and Pyrite)

Limestone (Micritic)

Sedimentary rock mainly composed of Calcium Carbonate (CaCO3)

Quartz Pebble

Silicon Dioxide (SiO2)

Limonite (Ironstone Concretion)

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

Chert (Limonite-stained)

Microcrystalline Quartz (SiO2) with iron oxides

Quartz (Milky or Druzy Quartz)

Silicon Dioxide (SiO2)

Gneiss

Metamorphic Gneiss

Chert (Flint)

Microcrystalline Quartz (SiO2)

Hematite or Goethite-rich Ironstone

Ironstone (Oxidized Iron Ore)

Quartzite Pebble

Quartzite (SiO2)

Quartzite Pebble

Metamorphosed Quartz Arenite (SiO2)