Mineral (Iron Ore)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Jasper

Jasper (Silicate mineral, SiO2)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

River Cobble (Basaltic/Andesitic)

Mafic Igneous Porphyritic Rock

Orange Quartzite (River Pebble)

Quartzite (SiO2 with iron oxide inclusions)

Limestone with Chert or Siltstone bands

Sedimentary carbonate rock (CaCO3) often with siliceous impurities

River Jasper (Chert/Chalcedony mix)

Silicon Dioxide (SiO2) with iron oxide and chlorite inclusions

Dendritic Agate

Silicon Dioxide with Manganese/Iron oxide inclusions (SiO2)

Ferruginous Sandstone (with possible Epidote/Chlorite coloring)

Sandstone (SiO2 dominated with Fe2O3 staining)

Amethyst

Quartz (SiO2) with trace iron impurities

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Amethyst (Tumbled)

Silicon Dioxide (SiO2 with iron impurities)

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe3+)

Rose Quartz

Silicon dioxide (SiO2)

Granite (Weathered)

Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz (Iron-Stained Quartz Pebble)

Silicon Dioxide (SiO2)

Banded Agate (Polished Slice)

Chalcedony (cryptocrystalline Quartz), SiO2

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (primarily SiO2)

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Quartzite (River Pebble)

Metamorphosed Quartz Sandstone (primarily SiO2)

Chert (Arrowhead Preform or Flake)

Microcrystalline Quartz (SiO2)

Jasper (Red/Brown Variety)

Jasper (Silicon Dioxide, SiO2 plus Iron Oxide impurities)

Sandstone (Ferruginous)

Arenite (complex silicate composition with iron oxides)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Red Jasper

Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)

Sandstone with Iron Oxide

Arenite (SiO2 with Fe2O3 staining)

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

Sandstone (with potential mineral inclusions)

Clastic sedimentary rock (primarily Quartz, SiO2)

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Jasper (Banded Jasper)

Silicon Dioxide (SiO2) with impurities

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Red Sandstone (Iron-rich Sandstone)

Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement

Amethyst (Rose-tinted/Pale variety)

Silicon Dioxide (SiO2) with iron impurities

Red Sandstone

Arenite (primarily SiO2 with hematite/iron oxide coating)

Basalt with Epidote/Chlorite

Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))

Dendritic Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides