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Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Anthracite Coal

Anthracite (Carbon)

Chert (Nodule)

Silicon Dioxide (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 based)

Carnelian Agate

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions

Hematite

Iron(III) oxide (Fe2O3)

Agate Jasper

Cryptocrystalline Quartz (SiO2) with impurities

Moonstone

Adularia or Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8), specifically with lamellar exsolution of albite and orthoclase.

Quartzite

Quartzite (SiO2)

Smoky Quartz (with possible Feldspar inclusions)

Silicon Dioxide (SiO2)

Quartz (Milky or Common Quartz)

Silicon Dioxide (SiO2)

Basalt

Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Quartzite (River Stone)

Quartzite (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Agate Geode Slice (with Druzy Quartz)

Silicon Dioxide (SiO2)

Chert / Jasper

Sedimentary Cryptocrystalline Quartz (SiO2)

Rough Amethyst Quartz

Silicon Dioxide with Iron impurities (SiO2)

Grey Slate

Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)

Jasper

Jasper (Silica/Quartz) - SiO2

Fossiliferous Limestone

Limestone with fossil inclusions (CaCO3)

Jasper

Jasper (Silica, SiO2)

Botryoidal Hematite (included in Quartz/Limonite matrix)

Fe2O3 (Hematite) on Quartz (SiO2) / Limonite

Jasper with Chalcedony

Silicon Dioxide (SiO2)

Blue Lace Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Jasper (Cream/Yellow variety)

Silicon Dioxide (SiO2) with impurities

Diamond (as set in a gold ring)

Carbon (C)

Quartzite

Quartzite (primarily SiO2)

Aquamarine

Beryl (Be3Al2Si6O18), specifically the blue-green variety

Chalcedony (specifically Agate or Flint)

Silicon Dioxide (SiO₂)

Garnet

Almandine (Fe3Al2(SiO4)3)

Red Shale

Fissile Siliciclastic Sedimentary Rock

Bauxite

Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)

Quartzite Pebble

Recrystallized Quartz (SiO2)

White Jade / Jadeite

NaAlSi2O6 (Sodium Aluminum Silicate)

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)