Synthetic (Not A Natural Rock)

Slate

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

Portable Ceramic Space Heater

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

Granite

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

Dark river-worn cobble, possibly basalt or fine-grained volcanic rock

Likely basaltic rock; exact identification requires a fresh surface and tests

Turquoise

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Lapis Lazuli

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

Tumbled carnelian agate with dark mineral inclusions

Carnelian, an orange variety of microcrystalline quartz (chalcedony), SiO₂; dark inclusions are likely iron oxides/hydroxides, possibly hematite, goethite, or a basaltic/matrix fragment

Turquoise

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

Gold Nugget

Native Gold (Au)

Asphalt (Aggregate)

Bituminous macadam / Concrete Aggregate

Tumbled carnelian agate

Cryptocrystalline chalcedony (SiO₂), an iron-colored variety of agate

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)

Clear Quartz (Crystal Quartz)

Silicon Dioxide (SiO2)

Pale green tumbled mineral fragment, likely serpentine or green calcite

Probable serpentine-group mineral (Mg3Si2O5(OH)4) or, less likely, calcite (CaCO3); identification is uncertain from the photograph

Dark rounded pebble, possibly basalt

Basalt (fine-grained mafic volcanic rock; identification tentative from photograph)

Prasiolite and Quartz Crystal Cluster

Quartz (SiO2); Prasiolite is a variety of Quartz

Weathered granite or granitic pegmatite cobble

Granite/granitic rock, composed mainly of quartz (SiO₂), feldspar, and minor biotite or other dark minerals; the reddish-brown areas may be iron-oxide staining or weathered accessory minerals

Granite

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

Tumbled blue quartzite or blue chalcedony (uncertain)

Quartz-rich rock; predominantly silicon dioxide (SiO₂)

Granite

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

Dark glassy pebble, possibly volcanic rock

Likely basalt or volcanic glass (var. obsidian), unconfirmed from image

Quartzite

Quartzite (SiO2)

Granite

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

Sandstone

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

Rounded river cobble, likely basaltic volcanic rock

Fine-grained mafic igneous rock; likely basalt or andesite

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone

Sandstone (lithified arenite/wacke)

Granite

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

Turquoise

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

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O

Rounded basalt cobble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with minor olivine or magnetite

Clear Quartz (Rock Crystal Fragments)

Silicon Dioxide (SiO2)

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Asphalt (Bituminous Concrete)

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

Smoky Quartz

SiO2 (Silicon Dioxide)

Weathered iron-rich sandstone or ferruginous siltstone

Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)

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)

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

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

Scoria (Red Lava Rock)

Scoria (Vesicular Basalt/Andesite)

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)