Synthetic (Not A Natural Rock)

Granite

Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)

Gold Nugget

Native Gold (Au)

Quartzite

Quartzite (primarily SiO2)

Quartz (various varieties)

SiO₂ (Silicon Dioxide)

Granite

Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O

Quartzite

Quartzite (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Sandstone

Quartz Arenite (a type of sandstone composed of more than 90% quartz)

Slate

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

Clear Quartz (Crystal Quartz)

Silicon Dioxide (SiO2)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone

Sandstone (lithified arenite/wacke)

Granite

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

Granite

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

Smoky Quartz

SiO2 (Silicon Dioxide)

Granite

Granite (a phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Granite

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

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Turquoise (beads)

Turquoise; CuAl6(PO4)4(OH)8·4H2O

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Laterite (iron-rich nodule, possibly Bauxite as a subtype)

Laterite (composed of various minerals including goethite, hematite, gibbsite, etc.)

Clear Quartz (Rock Crystal Fragments)

Silicon Dioxide (SiO2)

Asphalt (Bituminous Concrete)

Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)

Demantoid Garnet on Matrix

Demantoid (variety of Andradite Garnet) - Ca3(Fe3+)2(SiO4)3

Portable Ceramic Space Heater

Polished Acrylonitrile Butadiene Styrene (ABS) Plastic with Ceramic Heating Elements

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Turquoise

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

Turquoise

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

Scoria (Red Lava Rock)

Scoria (Vesicular Basalt/Andesite)

Sandstone

Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)

Slag Glass

Vitreous Silicate Residue

Sandstone

Arenite or Sandstone

Quartz (Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Diamond (Rough)

Diamond (C)

Tektite (likely Australite)

Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)