Sedimentary (Secondary Formation)

Red Jasper

Quartz (Silicon Dioxide) with Iron Oxide impurities (Fe2O3)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Botryoidal Agate

Chalcedony (Silicon Dioxide, SiO2)

Chert (Iron-stained)

Chert (Cryptocrystalline Quartz, SiO2)

Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')

Calcite (Calcium Carbonate, CaCO3)

Red Jasper

Silicon dioxide (SiO2) with hematite impurities

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Jasper with Iron Staining

Silicon Dioxide (SiO2) with impurities

Banded Agate

Sedimentary Cryptocrystalline Quartz (SiO2)

Azurite-Malachite (often a mixed specimen)

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Chert (specifically Jasper or Brown Chert node)

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Malachite

Malachite (Cu2CO3(OH)2)

Travertine

Terrestrial Sedimentary Limestone (CaCO3)

Chalk

Carbonate rock (mainly CaCO3)

Sandstone

Arenite (primarily SiO2)

Fossilized Fish (Lepidotes)

Lepidotes sp. (Order: Lepisosteiformes)

Sedimentary rock with quartz veining

Laminated siltstone or mudstone with hydrothermal quartz veins

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Sandstone

Arenite (composed primarily of SiO2)

Almandine Garnet in Schist

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

Sandstone

Arenite (SiO2 primarily)

Jasper (Iron-rich)

Silicon Dioxide (SiO2) with Fe2O3 (Hematite) impurities

Sandstone

Arenite (SiO2 based)

Limonite (often after Hematite or Goethite)

Limonite (FeO(OH)·nH2O)

Mica Schist with Garnet

Garnetiferous Mica Schist

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Yellow Jasper

Chalcedony (Silicon Dioxide with Iron inclusions), SiO2

Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

Sandstone (likely Navajo Sandstone)

Arenite (primarily SiO2)

Fossilized Coral (Petoskey Stone or Rugose Coral)

Antophyllum (Hexagonaria) or Scleractinia (CaCO3)

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone

Limonite (Ironstone)

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

Septarian Nodule (Yellow Calcite in Limestone)

Septarian Concretion (CaCO3 with Aragonite and Calcite)

Sandstone

Arenite

Sandstone

Arenite (SiO2 primarily)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 based)