Not A Rock (Man Made Polymer)

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)

Milky Quartz (among River Rock)

Quartz (Silicon Dioxide, SiO2)

Jasper (with Agate/Chalcedony inclusions)

Silicon Dioxide (SiO2)

Tree Agate

Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Granite

Plutonic felsic igneous rock

Jasper

Silicon dioxide / Chalcedony (SiO2)

Jasper

Silicon dioxide (SiO2)

River Stone (likely Quartzite or Chert)

Recrystallized Silicon Dioxide (SiO2)

Tiger's Eye

SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)

Jasper (Red/Yellow)

Silicon Dioxide (SiO2) with impurities

Tiger's Eye (likely Hawk's Eye variant)

Pseudomorph of Quartz after Crocidolite (SiO2)

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Red Jasper

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

Gneiss (specifically a Banded Gneiss cobble)

Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Riverstone (Quartzite or Siltstone cobble)

Quartzite (primarily SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

River Chalcedony / Agate

Chalcedony (Silicon Dioxide, SiO2)

Basalt (River Pebble)

Basalt (dominated by Plagioclase Feldspar and Pyroxene)

Ferruginous Sandstone

Arenite with Hematite/Limonite cement

Conglomerate

Conglomerate (clastic sedimentary rock)

Diabase (Dolerite) Cobble

Diabase / Dolerite

Rough Ruby

Corundum (Al2O3 with Chromium impurities)

Turquoise

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

Sandstone

Arenite (SiO2 based with mineral cement)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Vesicular Basalt (Lava Rock)

Aphanitic Mafic Igneous Rock

Porphyritic Basalt (Leopard Rock)

Porphyritic Mafic Volcanic Rock

Scoria (Red Lava Rock)

Scoria (Vesicular basaltic rock)

Basalt

Extrusive Mafic Igneous Rock (composed primarily of Plagioclase, Pyroxene, and Olivine)

Quartzite

Quartzite (SiO2)

Amygdaloidal Basalt with Epidote/Chlorite

Basalt (containing (Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH)))

Blue Apatite

Fluorapatite / Chlorapatite [Ca5(PO4)3(F,Cl,OH)]

Sandstone (Ferruginous)

Arenite with Iron-oxide inclusions (SiO2 primarily)

Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)