Mineral (Iron Ore)

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Meteorite (Chondrite)

Stony Meteorite (Ordinary Chondrite)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz with Fe2O3 staining)

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)

Jasper

Jasper (Silicon Dioxide, SiO2)

Chondrite Meteorite

Ordinary Chondrite (L or H Type)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Amethyst (Quartz)

Amethyst (Silicon Dioxide with Iron impurities, SiO2)

Ocean Jasper

Orbicular Jasper (Silicon Dioxide, SiO2)

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) - Microcrystalline Chalcedony

Marble

Recrystallized Calcite / Dolomite (CaCO3)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Turquoise in Matrix

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

Turquoise

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

Sandstone (Ferruginous)

Arenite (SiO2 with Iron Oxide impurities)

Tiger's Eye (specifically Blue Tiger's Eye / Falcon's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2)

Limestone (specifically Travertine or Tufa)

Calcium Carbonate (CaCO3)

Jasper

Silicon dioxide (SiO2) with impurities

Conglomerate

Conglomerate rock

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Red aventurine

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Sandstone

Arenite (SiO2 with Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Limonite inclusions

Ferruginous Sandstone

Clastic Sedimentary Rock (Iron-rich)

Jasper (Iron-rich)

Silicon Dioxide (SiO2) with Fe2O3 (Hematite) impurities

Sandstone (Ferruginous)

Arenite (with Hematite/Limonite cement)

Sandstone (River Rock)

Arenite (composed primarily of SiO2)

Amethyst/Smoky Quartz Cluster

Silicon Dioxide (SiO2)

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Citrine

Quartz (Silicon Dioxide - SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow Chert (Gold-colored River Pebble)

Microcrystalline Quartz (SiO2) with Limonite/Goethite staining

Mahogany Obsidian

Obsidian (SiO2 + Fe2O3)

Sandstone (specifically an Iron-Concretion)

Arenite with Iron Oxide (Limonite/Goethite) cementation

Strawberry Quartz (or Hematoid Quartz)

Silicon Dioxide (SiO2) with inclusions of Hematite or Goethite

Carnelian Agate

Chalcedony (SiO2 with Iron Oxide impurities)

Amethyst

Quartz (Silicon Dioxide with Iron impurities), SiO2

Sandstone (Ferruginous)

Arenite (Fe2O3 rich)