Not A Rock

River Rock / Stream Pebble

Fluvial Clast / Rounded Sedimentary Particle

Basalt

Basalt (Mafic volcanic rock)

Vesicular Basalt (Pumice-like)

Vesicular Basalt

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

Serpentine

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Desert Rose (Baryte or Selenite variant)

Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions

Granodiorite (Weathered)

Granodiorite

Granite

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)

Jasper

Silicon dioxide (SiO2)

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Yellow Quartzite (River Pebble)

Quartzite (SiO2)

Asphalt Chunk (with aggregate)

Bituminous concrete / Anthropogenic conglomerate

Quartzite Pebble

Quartzite (SiO2)

Granite or Porphyritic Igneous Rock (weathered)

Granitoid

Amber-bearing Coal/Sedimentary Rock

Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Limestone

Calcium Carbonate (CaCO3)

Serpentine

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3(Si, Al, Fe)2O5(OH)4

Granodiorite (Gneissic texture)

Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)

Basalt (Vesicular)

Basalt (Extrusive Volcanic Rock)

Quartz (Clear/Smoky Geode fragment)

Silicon Dioxide (SiO2)

Geode with Quartz and possibly Jasper/Hematite

Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides

Quartzite Pebble

Quartzite (mostly SiO2)

Granite

Granite

Basalt with inclusion

Basalt (Aphanitic-Porphyritic texture)

Basalt with Scoria

Amygdaloidal Basalt / Vesicular Basalt

Druzy Quartz on Chert/Chalcedony

Silicon Dioxide (SiO2)

Red Sandstone

Arenite (Iron-rich)

Quartz Geode

Silicon Dioxide (SiO2)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Quartz Geode (likely within Limestone or Dolomite matrix)

Quartz (SiO₂)

Sandstone

Arenite

Quartzite (Yellow/Orange variety)

Quartzite (primarily SiO2)

Vesicular Basalt (Lava Rock)

Vesicular Basalt

Desert Varnish on Sandstone

Ferromanganese coating on Quartz Arenite

Gravel or Crushed Stone

Fragmented Aggregate Stone

Vesicular Basalt (or Scoria)

Vesicular Basalt

Basalt

Basalt

Gneiss

High-grade regional metamorphic rock (Foliated)

Granite

Granite (Phaneritic intrusive igneous rock)

Basalt

Basalt