Quartzite River Rock with Dendrites
Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions
metamorphic
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Eclogite
Eclogite (comprising Omphacite and Garnet)
metamorphic
Pink Granite
Granite (Phaneritic igneous rock)
igneous
Pyrite
Iron Sulfide (FeS2)
mineral
Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
mineral
Coprolite
Coprolite
sedimentary
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous
Aventurine Quartz
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite organic gemstone
mineral
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
mineral
Pearl
Calcium Carbonate (CaCO3) + Conchiolin
mineral
Pearl
Aragonite and Calcite (CaCO3) with Conchiolin
mineral
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Pearl
Calcium carbonate (CaCO3) in the form of aragonite or calcite
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Quartzite
Quartzite (predominantly SiO2)
metamorphic
Pink Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)
mineral
Quartzite
Quartzite (predominantly SiO2)
metamorphic
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
mineral
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Pearl
Calcium Carbonate (Aragonite and Calcite), CaCO3
mineral
Onyx (Black Onyx)
Onyx (Silicon Dioxide, SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (White Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Druzy Quartz on Chert/Chalcedony
Silicon Dioxide (SiO2)
mineral
Chert
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Pegmatite
Coarse-grained Igneous Rock (Granitic Pegmatite)
igneous
Quartzite
Quartzite (composed mainly of SiO2)
metamorphic
Basalt
Basalt (Mafic volcanic rock)
igneous
Diamond
C (Carbon)
mineral
Sandy Ironstone
Ferruginous Sandstone
sedimentary
Basalt
Basalt
igneous
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous