Citrine (Iron-stained Quartz) rock specimen

Citrine (Iron-stained Quartz)

Silicon Dioxide (SiO2)

mineral

Botryoidal Pyrite rock specimen

Botryoidal Pyrite

Iron Sulfide (FeS2)

mineral

Basalt with Scoria rock specimen

Basalt with Scoria

Amygdaloidal Basalt / Vesicular Basalt

igneous

Tiger's Eye rock specimen

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with Iron Oxide)

metamorphic

Chevron Amethyst rock specimen

Chevron Amethyst

Silicon Dioxide (SiO2) with trace Iron impurities

mineral

Satin Spar (Selenite) rock specimen

Satin Spar (Selenite)

Gypsum (CaSO4·2H2O)

mineral

Chert (Black Chert/Flint) rock specimen

Chert (Black Chert/Flint)

Chert (Silicon Dioxide, SiO2)

sedimentary

Green Aventurine rock specimen

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

metamorphic

Moonstone (Feldspar) rock specimen

Moonstone (Feldspar)

Orthoclase feldspar, (K,Na)AlSi3O8

mineral

Chert / Flint rock specimen

Chert / Flint

Chert (SiO2)

sedimentary

Quartz Pebble rock specimen

Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Diorite (Salt and Pepper Rock) rock specimen

Diorite (Salt and Pepper Rock)

Diorite

igneous

Sandstone (Red Sandstone) rock specimen

Sandstone (Red Sandstone)

Arenite (SiO2 based with Fe2O3 staining)

sedimentary

Sandstone (specifically Red Sandstone) rock specimen

Sandstone (specifically Red Sandstone)

Arenite (SiO2 with Iron Oxide)

sedimentary

Sandstone (Quartzite-rich Pebble) rock specimen

Sandstone (Quartzite-rich Pebble)

Arenite (primarily SiO2)

sedimentary

Ironstone Concretion (Limonite/Goethite) rock specimen

Ironstone Concretion (Limonite/Goethite)

Iron oxide concretion (contains FeO(OH)·nH2O)

sedimentary

Chert (specifically Jasper/Flint pebble) rock specimen

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary

Chert (and Flint) rock specimen

Chert (and Flint)

Silicon Dioxide (SiO2)

sedimentary

Snowflake Obsidian rock specimen

Snowflake Obsidian

Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)

igneous

Chert / Jasper rock specimen

Chert / Jasper

Silicon Dioxide (SiO2)

sedimentary

Quartz Pebble (Chalcedony/Agate variety) rock specimen

Quartz Pebble (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

mineral

Chert (Jasper/Agate variety) rock specimen

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

sedimentary

Banded Agate (Carnelian type) rock specimen

Banded Agate (Carnelian type)

Agate (Cryptocrystalline Quartz, SiO2)

mineral

Red Jasper rock specimen

Red Jasper

Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)

sedimentary

Morganite (Pink Beryl) rock specimen

Morganite (Pink Beryl)

Beryllium aluminum silicate Be3Al2(SiO3)6

mineral

Conglomerate (River Rock) rock specimen

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

sedimentary

Pink Quartzite rock specimen

Pink Quartzite

Quartzite (mainly SiO2 with iron oxide impurities)

metamorphic

Jasper rock specimen

Jasper

Silicon dioxide (SiO2)

sedimentary

Chert (Nodular Chert) rock specimen

Chert (Nodular Chert)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

sedimentary

Red Jasper (Polished) rock specimen

Red Jasper (Polished)

Jasper (Iron-rich Microcrystalline Quartz, SiO2)

sedimentary

Chert (Jasper variation) rock specimen

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

sedimentary

Coralline Algae / Maerl rock specimen

Coralline Algae / Maerl

Lithothamnion (Biogenic Calcium Carbonate)

sedimentary

Chert (often called Flint when dark) rock specimen

Chert (often called Flint when dark)

Sedimentary cryptocrystalline quartz (SiO2)

sedimentary

Diorite rock specimen

Diorite

Diorite

igneous

Dolerite (Diabase) rock specimen

Dolerite (Diabase)

Dolerite / Diabase

igneous

Basalt rock specimen

Basalt

Extrusive mafic igneous rock

igneous

Diorite rock specimen

Diorite

Diorite (Intermediate intrusive igneous rock)

igneous

Carnelian Agate rock specimen

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

mineral

Sodalite Syenite rock specimen

Sodalite Syenite

Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)

igneous

Moonstone with Black Tourmaline rock specimen

Moonstone with Black Tourmaline

Orthoclase (KAlSi3O8) with Schorl inclusions

mineral

Dragon Blood Jasper rock specimen

Dragon Blood Jasper

Epidote-containing Quartz Chalcedony (SiO2 with Ca2(Al, Fe)3(SiO4)3(OH))

metamorphic

Chert (Iron-stained) rock specimen

Chert (Iron-stained)

Chert (Cryptocrystalline Silica, SiO2)

sedimentary