Turquoise (Green variety)
Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
mineral
Diamond
Diamond (pure carbon, C)
mineral
Carnelian Agate
Silicon Dioxide with Iron Oxide impurities (SiO2)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Opalite
Synthetic Opalised Glass
mineral
Chert (specifically Flint or Jasper variant)
Chert (Siliceous rock composed of microcrystalline Quartz, SiO2)
sedimentary
Quartz / Clear Quartz
Silicon Dioxide (SiO2)
mineral
Marble
Recrystallized Calcite (CaCO3)
metamorphic
Dalmatian Stone
Dalmatian Jasper (Aplitic Perthite)
igneous
Opalite
Man-made Glass (SiO2 + additives)
mineraloid (synthetic)
Red Moss Agate or Jasper-Agate
Silicon Dioxide (SiO2)
mineral
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
sedimentary or igneous (host environment)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
mineral
Green Quartzite (Aventurine-like)
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Red Jasper
Jasper (Silicon Dioxide) - SiO2
sedimentary
Red Jasper (possibly Orbicular)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Muscovite Mica (with Quartz)
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Ammonite Fossil (Polished Half)
Ammonoidea (subclass)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, e.g., Antigorite, Lizardite, Chrysotile)
metamorphic
Basalt with Quartz Vein and Weathering Crust
Amygdaloidal or Porphyritic Basalt
igneous
Basalt
Extrusive mafic igneous rock
igneous
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Glaucophane Schist (Blueschist)
Blueschist (Glaucophane-bearing schist)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Biotite Gneiss
Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)
metamorphic
Basalt
Vesicular Basalt
igneous
Muscovite Mica
Muscovite (Potassium Aluminum Silicate) - KAl2(AlSi3O10)(F,OH)2
mineral
Jet
Lignite (Anthracite-grade compact coal)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 in Matrix)
metamorphic
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
igneous
Granodiorite (Gneissic Pebble)
Granodiorite displaying minor foliation
igneous/metamorphic
Sedimentary rock with quartz veining
Laminated siltstone or mudstone with hydrothermal quartz veins
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Yellow Quartz (Citrine Quartzite)
Silicon Dioxide (SiO2)
metamorphic