This Is Not A Rock Or Mineral

Granite

Phaneritic Plutonic Felsic Rock (major components: SiO2 and Al2O3)

Fossil Sand Dollar (Echinoidea)

Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2) crystal conglomerate

Quartz Druze (on Matrix)

Silicon Dioxide (SiO2)

Quartzite (River Pebble)

Meta-quartzite (composed primarily of SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Sandstone (Pebble)

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Granite Cobble

Granite (Phaneritic Quartz-Feldspar Felsic Rock)

Quartz (specifically Citrine or Yellow Quartzite pebble)

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2)

Granite (Dioritic variant)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Basalt with Vesicular Texture

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Dalmatian Stone (often called Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

White Topaz

Topaz [Al2SiO4(F,OH)2]

Quartz Pebble (Milky Quartz)

Silicon Dioxide (SiO2)

Blue Lace Agate (Polished Point)

Silicon Dioxide (SiO2) - Variety of Chalcedony

White Precious Opal

Hydrated Silica (SiO2·nH2O)

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Sandstone (specifically Cross-bedded Sandstone)

Arenite (composed primarily of SiO2)

Sandstone (likely Fossiliferous)

Arenite / Sedimentum arenaceum

Moonstone (bead form)

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

Basalt

Basalt (Mafic Extrusive)

Unakite

Epidotized Granite

Granite

Phaneritic plutonic rock (SiO2 typically >69%)

Milky Quartz

Silicon Dioxide (SiO2)

Specular Hematite

Hematite (Fe2O3)

Milky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)

Granite

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

Amethyst

Amethyst (Silicon Dioxide with Iron impurities, SiO2)

Crazy Lace Agate

Agate (Cryptocrystalline Quartz), Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Shale

Fissile mudstone (Shale)

Quartzite

Quartzite (primarily SiO2)

Diorite (River Pebble)

Phaneritic Intermediate Plutonic Rock (Diorite)

Granite

Course-grained intrusive igneous rock

Sodalite

Na8(Al6Si6O24)Cl2