This Is Not A Rock Or Mineral

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Muscovite Mica

Muscovite / KAl2(AlSi3O10)(OH)2

Smoky Quartz

Silicon Dioxide (SiO2)

Amethyst (Purple Quartz)

Silicon Dioxide (SiO2) with iron impurities

Olivine Basalt

Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Chert (Nodule)

Silicon Dioxide (SiO2)

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite

Flowerstone

Porphyritic Basalt or Porphyritic Andesite

Basalt (with possible quartz veinsing)

Basalt

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Sandstone

Arenite (primarily SiO2)

Schorl (Black Tourmaline) in Quartz or Feldspar Matrix

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl) in Granitic Pegmatite

Ruby in Zoisite (Anyolite)

Corundum var. Ruby in Zoisite (Al2O3 + (Ca2Al3(SiO4)3(OH)))

Conglomerate (Puddingstone)

Conglomerate (specifically, clastic sedimentary rock)

Sandstone

Sandstone (clastic sedimentary rock, predominantly SiO2)

Rose Quartz

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

Quartz (Milky and Smoky variety)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Granite

Phaneritic Plutonic Felsic Rock

Quartz (Common Milky Quartz)

Silicon Dioxide (SiO2)

Silty Shale

Silty Shale (Fissile Sedimentary Rock)

Geode (unopened) or Calcareous Nodule

Siliceous or Calcareous Concretion/Nodule

Granite

Phaneritic Igneous Rock (Granite)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (Main mineral constituents: Muscovite/Biotite, Quartz, Feldspar)

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Pink Anthracite Coal (dyed)

Anthracite Coal (Artificially Colored)

Aventurine

Aventurine Quartz (SiO2 with inclusions)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Amethyst

Silicon dioxide with iron impurities (SiO2)

Kimberlite

Kimberlite (Potassic ultramafic volcanic rock)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)

Sandstone

Arenite (variable SiO2 composition)

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)