Mineral Like Byproduct (Often Mistaken For Igneous Rock Or Meteorite)

Sandstone

Arenite (primarily SiO2)

Obsidian

Volcanic Glass (Amorphous SiO2)

Banded Sandstone (Differential Weathering)

Clastic Sedimentary Rock (primarily SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Quartz Pebble

Silicon Dioxide (SiO2)

Granite

Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Anthracite Coal

Anthracite (a variety of coal, predominantly carbon)

Fluorite (Rainbow Fluorite Point)

Calcium Fluoride (CaF2)

Moonstone (bead form)

Potassium Aluminum Silicate (KAlSi3O8) - a variety of Orthoclase Feldspar

Tree Agate (Dendritic Agate/Quartz)

Silicon Dioxide (SiO2) with trace Manganese or Iron oxide inclusions

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ruby (Corundum)

Corundum (Aluminum Oxide) with chromium trace elements, Al2O3

Basalt with Quartz/Calcite Veins

Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions

Blue Star Sapphire

Corundum (Al2O3)

Banded Gneiss

Gneiss (complex metamorphic silicate rock)

Gneiss (Schistose)

Gneiss

Sandstone (Wonderstone)

Silicified Sandstone / Orthoquartzite with Liesegang rings

Flowerstone

Porphyritic Basalt or Porphyritic Andesite

Ferruginous Sandstone (Ironstone)

Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))

Agate Jasper

Cryptocrystalline Quartz (SiO2) with impurities

Quartz (specifically Milky or Clear Quartz)

Silicon Dioxide (SiO2)

Gold Nugget

Native Gold (Au)

Shale with Pyrite

Clastic sedimentary rock containing Iron Disulfide (FeS2)

Blue Zircon

Zirconium Silicate (ZrSiO4)

Bauxite

Bauxite (Mixture of Hydrous Aluminum Oxides)

Sandstone

Arenite (SiO2 based with mineral cement)

Basalt with Weathering Crust

Extrusive mafic volcanic rock

Basalt with Amygdaloidal Inclusions

Aphanitic Mafic Volcanic Rock (Basalt)

Milky Quartz

Silicon Dioxide (SiO2)

Granodiorite (Gneissic texture)

Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)

Epidote in Quartz

Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)

Vesicular Basalt (Amygdaloidal)

Vesicular Basalt (Fe-Mg rich extrusive volcanic rock)

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock

Sandstone (Weathered Coastal Boulder)

Arenite (composed primarily of SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Tumbled)

Silicon Dioxide (SiO2)

Obsidian

Volcanic Glass (70-75% SiO2)

Red Jasper

Jasper (Silicon Dioxide with Iron Oxide impurities), formula: SiO2

Sandstone

Arenite (primarily SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Granite / Gneiss Complex

Felsic Plutonic Rock (Granite) or High-grade Metamorphic Rock (Gneiss)