Igneous Or Sedimentary (Anthropogenic Modification)

Clear Quartz Crystal (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Milky Quartz (with trace inclusions)

Silicon Dioxide (SiO2)

Milky Quartz with Chlorite/Moss Infusions

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Granite

Granite (a common term for a felsic intrusive igneous rock)

Sandstone (Red Arkose)

Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)

Garnet

Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Goethite/Hematite shell with Sandstone core)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Sodalite

Na8(Al6Si6O24)Cl2

Caribbean Calcite

Calcium Carbonate with Argonite (CaCO3)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Granite Pebble

Felsic intrusive igneous rock

Dolerite (Diabase)

Dolerite / Diabase

Granite (with Almandine Garnet inclusions)

Granite composed primarily of Quartz (SiO2), K-Feldspar (KAlSi3O8), and Almandine Garnet (Fe3Al2(SiO4)3)

Granite (likely a river or beach pebble)

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

Pegmatite

Granitic Pegmatite

Epidote

Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Amethyst

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Corundum (Sapphire in Host Rock)

Corundum (Aluminum Oxide, Al2O3)

Blue Apatite

Apatite-(CaF), Ca5(PO4)3F (Calcium Fluorophosphate)

Yellow Agate

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Rose Quartz

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

Hypersthene

Hypersthene (Magnesium Iron Silicate - (Mg,Fe)SiO3)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Sodalite

Na8(Al6Si6O24)Cl2

Quartz with Muscovite Mica

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride (KAl2(AlSi3O10)(F,OH)2)

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Limonite (Ironstone Concretion)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Granite (Weathered River Rock)

Plutonic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Diorite (or salt-and-pepper granite pebble)

Phaneritic Igneous Rock (Intermediate Composition)

Snowflake Obsidian

Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)

Granite

Granite (Phaneritic intrusive igneous rock)

Labradorite (Larvikite variety)

(Na,Ca)(Al,Si)4O8 (Plagioclase Feldspar)

Sandstone (Quartzite-rich Cobble)

Clastic sedimentary rock (primarily SiO2)

Labradorite (likely Black Labradorite or Larvikite)

Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Porphyritic Basalt (likely Chinese Writing Stone)

Porphyritic Basalt / Plagioclase Feldspar in Basal Matrix

Arfvedsonite in Quartz (also known as Eudialyte/Garnet Syenite variety)

Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2] within a silicate matrix