This Image Does Not Display A Rock, Mineral, Or Geological Specimen. It Shows A Human Hand Wearing A Ring.

Jasper (Milky/Cream Variety)

Silicon Dioxide (SiO2) - variety of Chalcedony

Gneiss (specifically Micaceous Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Moss Agate

Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)

Petrified Wood

Silicified Wood (primarily SiO2)

Ocean Jasper

Silicon Dioxide (SiO2) with various inclusions

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Agate (Carnelian-Blue Agate mix)

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2) with ferric iron impurities

Quartz (Milky/Gold-stained)

Silicon Dioxide (SiO2)

Sandstone

Arenite (Clastic Sedimentary Rock)

Pink Anthracite Coal (dyed)

Anthracite Coal (Artificially Colored)

Quartz Geode (partially formed)

Silicon Dioxide (SiO2)

Granite Pebble (Pink Granite)

Phaneritic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Gold Ore in Quartz

Auriferous Quartz (Gold: Au; Quartz: SiO2)

Granite

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

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone with Liesegang Rings

Arenite with Iron Oxide Liesegang Banding

Granite Gneiss

Gneiss (high-grade metamorphic rock)

Botryoidal Quartz / Calcite Geode crust

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Granite (Pegmatitic)

Phaneritic Felsic Igneous Rock

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)

Blue Apatite

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

Sandstone (Ferruginous)

Arenite with Iron Oxides

Quartz (Citrine or Iron-Stained variety)

Silicon Dioxide (SiO2)

Feldspathic Granite (likely Syenite or Granite Pegmatite)

Phaneritic Acidic Igneous Rock (KAlSi3O8 dominant with SiO2)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Quartz

SiO₂ (Silicon Dioxide)

Petrified Wood

Silicified Wood (primarily SiO2)

Agate

Agate (Silicon Dioxide - SiO2)

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Quartz (beads)

SiO2 (Silicon Dioxide)

Basalt

Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)

Chert (specifically Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Sandstone

Sandstone (principally SiO2)

Sandstone (Quartzose)

Arenite (SiO2 principal)

Placer Gold Nugget

Native Gold (Au)

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Conglomerate

Conglomerate

Jasper

Silicon dioxide (SiO2)

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)