Sedimentary (Secondary Mineral Formation)

Magnetite (likely with weathered Limonite/Hematite)

Magnetite (Fe3O4) with iron oxide weathering

Banded Chert

Microcrystalline Quartz (SiO2)

Ironstone Concretion (Moqui Marble type)

Iron oxide concretion (Goethite/Hematite and Sandstone)

Blue Calcite

Calcium Carbonate (CaCO3)

Fossil / Permineralized Bone

Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)

Pink Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Red Sandstone

Sandstone (mainly SiO2 with Iron Oxide cement)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Nodular)

Chert (Microcrystalline Quartz, SiO2)

Black Kyanite

Kyanite (Al2SiO5) with carbonaceous inclusions

Gneiss

Gneiss (High-grade regional metamorphic rock)

White Quartz

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide (SiO2)

Red Jasper

Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)

Fossilized Coral (Petoskey Stone or Rugose Coral)

Antophyllum (Hexagonaria) or Scleractinia (CaCO3)

Sandstone

Arenite (primarily SiO2)

Jasper (Red Jasper with Quartz veins)

Jasper (Silicon Dioxide, SiO2)

Kidney Stone (Renal Calculus)

Calcium oxalate monohydrate (Whewellite) / CaC2O4·H2O

Red Sandstone

Clastic Terrigenous Sedimentary Rock (composed mostly of SiO2 with Fe2O3)

Chert (Jasper variation)

Chert (Silicate mineral, SiO2)

Mica Schist with Garnet

Garnetiferous Mica Schist

Ironstone Concretion

Siderite or Limonite Concretion

Green Fluorite

Calcium Fluoride (CaF2)

Chert (vuggy variety)

Microcrystalline silica (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz Vein in Sandstone

Sandstone with Hydrothermal Quartz (SiO2)

Fancy Jasper (Ocean Jasper or River Jasper variant)

Silicon Dioxide with inclusions (SiO2)

Aragonite Star Cluster (or Aragonite Sputnik)

Aragonite (Orthorhombic Calcium Carbonate, CaCO3)

Specular Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Carnelian Agate

Carnelian (Silicon Dioxide, SiO2)

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Chert (variously known as Flint or Microcrystalline Quartz)

Silicon dioxide (SiO2)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Red Sandstone

Arenite (predominantly Quartz with Hematite cementation)

Sandstone

Arenite (primarily SiO2)

Sandstone (likely Navajo Sandstone)

Arenite (primarily SiO2)

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone