Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Sandstone

Arenite (composed primarily of SiO2)

Quartz-veined Basalt

Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein

Chert (Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Ferruginous)

Arenite (with high iron oxide content)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Blue Quartzite

Quartzite (specifically a variety enriched with blue-coloring minerals)

Basalt with Quartz Vein

Basalt (SiO2 vein inclusion)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Chert (Hagstone/Gasket Rock variant)

Chert (SiO2)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO₂)

Bloodstone

Heliotrope (cryptocrystalline Quartz, SiO2 with inclusions of Hematite)

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)

Fuchsite Quartzite

Fuchsite-bearing Quartzite

Chert (often called Flint or Jasper when red)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Banded)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Vesicular Basalt (Lava Rock)

Aphanitic Mafic Igneous Rock

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (mostly SiO2)

Chert (Iron-stained)

Chert (SiO2)

Vesicular Basalt

Mafic Volcanic Rock (Basalt)

Greenstone / Serpentinite

Serpentinite (composed primarily of minerals from the serpentine group Mg3Si2O5(OH)4)

Conglomerate (Red Sandstone variety)

Clastic Sedimentary Rock (Conglomeratic Sandstone)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)

Sandstone

Arenite (SiO2 principal component)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Quartz Pebble (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Sandstone (Quartzite Pebble)

Arenite (SiO2)

Pink Granite

Granite (Phaneritic intrusive rock)

Sandstone

Arenite (Sedimentary rock composed of sand-sized minerals or rock grains)

Chalcedony (Botryoidal/Drusy Quartz)

Silicon Dioxide (SiO₂)

Banded Agate (Onyx type)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Druzy Quartz on Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Quartz on Host Rock

Silicon Dioxide (SiO2)

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)