Not A Geological Specimen

Quartz (Yellow/Tan Quartzite Pebble)

Silicon Dioxide (SiO2)

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

Milky Quartz with Chlorite Schist Inclusions

Quartz (SiO2) with Chlorite Group silicates (typically (Mg,Fe)3(Si,Al)4O10(OH)2)

Lapis Lazuli

Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])

Garnet

Almandine (Fe3Al2(SiO4)3)

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (SiO2 with minor iron impurities)

Chert River Pebble

Microcrystalline Quartz (SiO2)

Quartz (Milky and Smoky variety)

Silicon Dioxide (SiO2)

Chert / Chalcedony (likely carnelian or flint variety)

Silicon Dioxide (SiO2)

Stromatolite

Biogenic Sedimentary Rock (Lithified microbial mat)

Septarian Nodule (or Mudstone with Septarian Cracking)

Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Claystone)

Fossil Coral (Rugose Coral)

Rugosa (extinct order of solitary and colonial corals)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Gold Ore in Matrix

Native Gold (Au) in Quartz/Limonite host rock

Amygdaloidal Rhyolite

Amygdaloidal felsic extrusive rock

Emerald In Matrix (Quartz/Calcite)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Petrified Wood

Silicified Wood (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Ruby in Kyanite

Corundum in Disthene (Al2SiO5 + Al2O3)

Agate with Quartz Druzy

Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties

Quartz Geode

Silicon Dioxide (SiO2)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

River Rock (Granite Cobble)

Granite (Phaneritic Quartz-Feldspar-Mica intrusive rock)

Pyrite in Matrix (Quartz/Schist)

Iron Sulfide (FeS2)

Granite River Cobble

Phaneritic Felsic Igneous Rock

Limestone Pebble with Crinoid Fossil

Calcium Carbonate (CaCO3) - Fossiliferous Limestone

Chalcedony (Agate/Quartz)

Silicon Dioxide (SiO2)

Diamond (Set in jewelry)

Cubic Carbon (C)

Green Fluorite

Calcium Fluoride (CaF2)

Opalite

Synthetic Opalised Glass

Agate Geode

Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety

Quartz Vein in Metamorphic Rock

Silicon Dioxide (SiO2) within Metasedimentary host

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Granite

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

Septarian Nodule (Dragon Stone) sphere

Septarian concretion (Calcite, Aragonite, and Limestone)

Pink Granite

Potassium Feldspar-Rich Granite

Quartzite Pebble

Recrystallized Quartz (SiO2)

Quartz Pebble (Chert/Chalcedony)

Silicon Dioxide (SiO2)

Quartzite with Iron inclusions

Metamorphosed Sandstone (SiO2 with Fe2O3)

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling