Not A Natural Rock (Man Made Composite)

Quartzite

Quartzite (primarily SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Pebble

Clast (specifically a granule or small pebble)

Turquoise

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

Clear Quartz

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Sandstone (with possibly iron oxides and other minerals)

Sandstone

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, chlorite, and micas)

Granite

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

Ironstone (Limonitic Shale)

Ferruginous Siltstone / Goethite-rich Sedimentary Rock

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Schist (Kyanite Schist)

Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Blue Sapphire

Corundum (Al2O3)

Agate Slices and Clear Quartz Points

Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)

Granite

Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)

Lapis Lazuli

Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)

Gold Nugget

Native Gold (Au)

Quartzite Pebble

Quartzite (SiO2 with minor impurities)

Clear Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Pink Fluorite

Fluorite (Calcium Fluoride) - CaF2

Black Onyx

Silicon dioxide (SiO2) with parallel banded structure

Turquoise

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

Carnelian and White Quartz Bracelet

Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz

Turquoise

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

Turquoise (Green variety)

Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Chrysocolla in Jasper (Chryso-Jasper)

Cu2-xAlx(H2-xSi2O5)(OH)4·n H2O (Chrysocolla) + SiO2 (Jasper)

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Turquoise

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

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Ferruginous Sandstone (Iron-rich Sandstone)

Ferruginous Arenite

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (SiO2 with Iron Oxide impurities)

Red Granite

Felsic intrusive igneous rock (K-feldspar rich Granite)

Glauconitic Sandstone (Greensand)

Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)