Not A Natural Rock (Man Made Composite)

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide inclusions

Sandstone

Arenite

Pink Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)

Cat's Eye Moonstone (Simulated/Synthetic or natural Cat's Eye Quartz/Glass)

There is no single scientific name. The appearance suggests either: Moonstone (feldspar group), Cat's Eye Quartz (SiO2), Apatite (Ca5(PO4)3(F,Cl,OH)), or most likely a synthetic material such as Fiber Optic Glass or 'Opalite' (a type of glass).

Granite

Phaneritic Plutonic Felsic Rock (SiO2 > 69%)

Sandstone

Arenite (primarily SiO2)

Basalt (Water-worn pebble)

Basalt (Mafic Extrusive Rock)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

Shungite

Non-crystalline carbon (Fullerenes / Carbon-60)

Granite

Phaneritic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)

Pink Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Vesicular Basalt with Quartz/Chalcedony

Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)

Granodiorite

Granodiorite

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)

N/A (Non-Geological Object)

Slag (Industrial Byproduct)

Ferrous/Non-ferrous Silicate

Sandstone

Arenite (primarily composed of SiO2)

Granite

Phaneritic intrusive igneous rock (Quartz, Feldspar, Mica)

Clear Quartz

Crystalline Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Serpentine

Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)

Flint (or Chert)

Cryptocrystalline Quartz (SiO2)

Native Gold (in the form of jewelry)

Gold (Au)

Limestone

Calcium Carbonate (CaCO3)

Diamond (Set in jewelry)

Cubic Carbon (C)

Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)

Diorite (Igneous rock, intrusive, intermediate composition)

Granite

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

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Ruby in Zoisite

Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende

Limestone

Calcium carbonate (CaCO3)

Basalt

Basalt (containing mainly Plagioclase feldspar and Pyroxene)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)

Emerald In Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Sandstone (likely Arkosic or Lithic Sandstone)

Arenite (SiO2 based with mineral inclusions)

Granitic Gneiss

Gneiss (High-grade Metamorphic Rock)

Quartzite Pebble

Metamorphic Quartz (SiO2)

Olivine (Peridot)

Olivine Group (Mg,Fe)2SiO4

River Pebble (Greywacke or Basaltic)

Massive Greywacke or Basaltic Andesite

Blue Agate (Dyed Chalcedony)

Silicon Dioxide (SiO2)