Sedimentary Rock Or Mineral (Depending On Origin And Purity)

Sandstone (likely Arkose)

Arenite (composed mainly of SiO2 with Feldspar)

Fossilized Shark Tooth in Matrix

Otodus sp. (likely Otodus obliquus)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Granitic Pegmatite

Granitic Pegmatite with Quartz and Feldspar

Limestone

Calcium Carbonate (CaCO3)

Foliated Metamorphic Rock (likely Gneiss or Schist)

Gneissic Metamorphic Rock

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (Siliclastic sedimentary rock), SiO2 + various minerals

Jasper with Iron Staining

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) with Quartz crystals

Sandstone (Pet Rock)

Clastic sedimentary rock (primarily SiO2)

Quartzite

Metamorphic rock (primarily SiO2)

Black Star Diopside

Diopside (CaMgSi2O6) with asterism

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Limestone Breccia

Sedimentary Breccia (Calcareous)

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

Sandstone (likely Arkosic)

Clastic Sedimentary Rock (Sandstone)

Sandstone (Beach Pebble)

Clastic sedimentary rock (primarily Quartz and Feldspar)

Serpentine

Serpentinite (group of minerals: (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Quartzite (tumbled or water-worn)

Quartzite (composition: SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (SiO2 primarily)

Quartzite (Milky)

Metamorphic rock predominantly composed of Quartz (SiO2)

Blue Tiger's Eye

Crocidolite in Quartz (altered)

Conglomerate

Conglomerate (clastic sedimentary rock)

Shale

Fissile mudstone (primarily clay minerals and silt-sized quartz)

Jasper with Manganese Dendrites

Silicon Dioxide (SiO2) with Oxide Mineral Inclusions

Pink Granite

Phaneritic Plutonic Felsic Igneous Rock (Granite)

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Quartzite

Quartzite (SiO2)

Epidote

Epidote Group (e.g., Clinozoisite, Epidote, Piemontite), Epidote formula: Ca2(Al,Fe)3(SiO4)3(OH)

Granite Pebble

Granite (a plutonic igneous rock composed primarily of quartz, feldspar, and mica/amphibole)

Sandstone (likely Quartzose type)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (SiO2 based)

Ironstone Concretion (Nutstone)

Ironstone (with High Limonite/Hematite Content)

Sandstone

Arenite (primarily SiO2)

Quartzite (specifically a river-worn cobble)

Quartzite (primarily Silicon Dioxide, SiO2)

Jade (Jadeite/Nephrite)

NaAlSi2O6 (Jadeite) / Ca2(Mg,Fe)5Si8O22(OH)2 (Nephrite)

Quartz

Silicon Dioxide (SiO2)