Non Geological

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Quartz Veinated Sandstone or Siltstone

Silicon Dioxide (SiO2) within a clastic sedimentary matrix

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

André's Landing Rock (Sandstone Boulder)

Newark Supergroup Sandstone (likely Stockton Formation)

Sandstone (with Limonite staining)

Arenite (primarily SiO2 with FeO(OH)·nH2O)

Moqui Marble

Ironstone Concretion (Limonite/Hematite over Sandstone)

Almandine Garnet

Almandine, Fe3Al2(SiO4)3

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

Moqui Marble (Shaman Stone)

Ironstone Concretion (Fe2O3 - Hematite/Goethite shell with Sandstone core)

Diamond in Kimberlite

Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)

Porphyritic Basalt (with Quartz or Calcite inclusion)

Porphyritic Basalt (Matrix: SiO2/MgO/FeO, Phenocryst: likely Quartz or Calcite)

Vesicular Basalt with Opal or Quartz

Vesicular Basalt (Amorphous SiO2.nH2O if Opal)

Amygdaloidal Basalt

Amygdaloidal Basalt (Ca-rich Plagioclase, Pyroxene, and Olivine)

Amygdaloidal Basalt

Basalt with secondary amygdule minerals (likely Epidote or Chlorite)

Granite

Granite (Felsic intrusive igneous rock)

Petrified Wood

Silicified Wood (SiO2)

Quartz Geode (partially formed)

Silicon Dioxide (SiO2)

Sandstone (Quartzose Sandstone)

Clastic Terrigenous Sedimentary Rock (primarily SiO2)

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Banded Iron Formation (BIF) / Iron Ore

Hematite-Magnetite BIF (Fe2O3 / Fe3O4 mixed with SiO2)

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Chert (Brown Variety)

Microcrystalline quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Epidote Water-Worn Pebble

Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Quartz Geode

Crystalline Quartz (Silicon Dioxide, SiO2)

Crinoid Fossil Stem Segment

Class Crinoidea (Echinodermata)

Bored Siltstone (Holey Rock)

Siltstone with Pholad borings (Lithophaga/Pholadidae trace fossils)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Mica Schist (with Muscovite)

Muscovite/Quartz Schist (KAl2(AlSi3O10)(OH)2)

Fossiliferous Sedimentary Rock (Coquina/Limestone)

Fossiliferous Calcarenite / Bioclastic Limestone

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2 - Silicon Dioxide)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within a metamorphic matrix

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Quartz Geode (partially opened)

Silicon Dioxide (SiO2) with iron staining

Sandstone

Arenite (Siliclastic Sedimentary Rock)

Granite (Micro-specimen)

Plutonic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Mixed Mineral Specimens

Mixed Silicates, Oxides, and Phosphates (SiO₂, Ca₅(PO₄)₃(F,Cl,OH), Na₈Al₆Si₆O₂₄Cl₂, etc.)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Quartz (Milky or Common Quartz)

Silicon Dioxide (SiO2)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)