Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Botryoidal Black Chalcedony Geode (Black Grape Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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.

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2)

Cinnabar in Quartz

Silicon Dioxide (Quartz, SiO2) with Mercury Sulfide inclusions (Cinnabar, HgS)

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Iron-stained Quartz (Gossan/Limonite-coated Quartz)

Silicon Dioxide (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)

Chert (variations include Flint or Jasper)

Cryptocrystalline Quartz (SiO2)

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

Basalt (Polished pebble)

Basalt (Aphanitic mafic volcanic rock)

Petrified Wood

Silicified Wood (SiO2)

Rose Quartz

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

Quartz / Limestone Gravel

SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide impurities

Limestone

Calcium Carbonate (CaCO3)

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Quartz (Iron-Stained or Milky Quartz)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)

Quartzite Pebble

Metamorphic Quartz (SiO2)

Basalt

Basalt (Aphanitic mafic volcanic rock)

Carnelian Agate

Silicon Dioxide (SiO2) with Iron Oxide impurities

Quartzite (Ferruginous)

Quartzite (major component SiO2 with Fe2O3 impurities)

Agate (specifically a Blue Agate Geode Slice)

Chalcedony (cryptocrystalline variety of Quartz); SiO2

Jasper Beach Pebble

Silicon Dioxide (SiO2) - Macro-crystalline Quartz

Chert (Nodule)

Microcrystalline quartz (SiO2)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Quartzite (Water-worn Cobble)

Quartzite (Composition: 90%+ SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Yellow Jasper

Jasper (Silica-rich Microcrystalline Quartz, SiO2)

Petrified Wood

Silicified wood (Quartz, SiO2)

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Sandstone (Tumbled/River Pebble)

Arenite (composed primarily of SiO2)

Botryoidal Quartz / Calcite Geode crust

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Granite Pebble

Granite (Phaneritic Acidic Igneous Rock)

Milky Quartz

Silicon Dioxide (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (High Silica / Iron Oxide)

Granitic Gneiss

Gneiss (Polymetamorphic Granitic Gneiss)