Not A Natural Rock

Granite

Phaneritic plutonic felsic igneous rock

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Greywacke (River Siltstone)

Lithic Wacke (Sandstone subfamily)

Green Aventurine

Silicon Dioxide with Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Turquoise

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

Rock crystal quartz fragment

Quartz (silicon dioxide, SiO₂)

Weathered quartz-rich rock, possibly pegmatite or quartzite

Quartz (SiO₂)-rich aggregate; exact identification is uncertain from the photograph

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Agate

Silicon Dioxide (Chalcedony), SiO2

Blue Sapphire (Raw)

Corundum (Al2O3)

Turquoise

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

Peacock Ore (Bornite or Chalcopyrite treated with acid)

Bornite (Cu5FeS4) or Acid-washed Chalcopyrite (CuFeS2)

River Cobble (Basalt / Gabbro)

Mafic Igneous Rock (Basaltic / Gabbroic Composition)

Rounded quartz-rich cobble, likely granite-derived stone

Granite or granitic gneiss, composed mainly of quartz, feldspar, and minor mica

Tektite (Indochinite)

Tektite (Amorphous silica glass, SiO2 with impurities)

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

Weathered granite-like rock

Granite, likely biotite-bearing; exact identification is uncertain from the image

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

Clear Quartz

Silicon Dioxide (SiO2)

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Water-worn basalt cobble

Basalt; chiefly plagioclase feldspar, pyroxene, and minor olivine/iron oxides

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Weathered quartz-rich rock, possibly sandstone or quartzite

Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite

Amethyst-rich vesicular volcanic rock (probable amethyst basalt/scoria)

Quartz (SiO₂) in vesicular basaltic volcanic rock; precise identification requires testing

Turquoise in Matrix

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

Granite

Granite (composed mainly of Quartz, Alkali Feldspar, and Plagioclase)

Weathered metallic-looking rock, possibly hematite-bearing ironstone

Hematite-rich ironstone; hematite Fe₂O₃, potentially with magnetite Fe₃O₄ and quartz

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

Diamond (or Cubic Zirconia)

Cubic Carbon (C) or Zirconium Dioxide (ZrO2)

Aura Quartz (Titanium/Gold coated)

Silicon Dioxide (SiO2) with metallic vapor deposition

Unakite-like granite with a white feldspar inclusion

Granite, chiefly quartz–feldspar–biotite; pale inclusion likely albite/orthoclase feldspar

Green aventurine beads

Quartz (SiO₂), typically green quartzite/aventurine with fuchsite mica inclusions

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Schist

Crystalline Metamorphic Rock (Schistose)

Diamond

C (Carbon)

Polished ocean jasper (orbicular jasper), probable

Microcrystalline quartz (SiO₂), chiefly chalcedony with iron-oxide and other mineral inclusions

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 dominated)