Not A Rock Or Mineral

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Rough Quartz (or Quartzite pebble)

Silicon Dioxide (SiO2)

Diorite (with Iron Staining)

Phaneritic Intermediate Igneous Rock

Gneiss

Gneiss

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Granite (specifically the Ubatuba variety)

Phaneritic Igneous Rock (Granodiorite/Monzogranite)

Milky and Citrine-type Quartz

Silicon Dioxide (SiO2)

Chalcanthite (Likely Synthetic/Lab-Grown)

Hydrated copper(II) sulfate (CuSO4·5H2O)

Quartz Pebble

Silicon Dioxide (SiO2)

Granite

Granite (Felsic Plutonic Rock)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

River Cobble (Phyllite or Quartzite)

Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)

Granite

Phaneritic Granitoid (Primary minerals: Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)

River Rocks (Black)

Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts

Milky Quartz (with trace inclusions)

Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)

Turquoise and Red Coral

Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)

Quartz (specifically Milky or Clear Chunk)

Silicon Dioxide (SiO2)

Granite

Granitic intrusive igneous rock

Sandstone

Arenite

Vesicular Basalt (Iron-rich)

Scoriaceous Basalt / Oxidized Vesicular Basalt

Epidote (Unakite-related)

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Basalt with Jasper Veining

Basaltic Rock with Cryptocrystalline Quartz (SiO2)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Gold Ore in Quartz

Native Gold (Au) in Quartz (SiO2)

Quartz / Vein Quartz

Quartz (Silicon Dioxide, SiO2)

Bumblebee Jasper

Calcite-Auripigment-Pyrite-Realgar assemblage (Carbonate/Sulphide mixture)

Mica Schist with Pyrite

Muscovite/Biotite Schist with Iron Sulfide (FeS2)

Petrified Wood

Silicified Wood (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Agate Geode

Microcrystalline Quartz (SiO2)

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

Diabase (Greenstone)

Diabase (also known as Dolerite)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Sandstone with Ironstone Banding

Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)