Mineral (Or Mineraloid If Microcrystalline)

Red Jasper (Skull Carving)

Jasper, a cryptocrystalline variety of Quartz (SiO2)

Ironstone Concretion

Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)

Chert (and/or River Pebble)

Microcrystalline quartz (SiO2)

Chert (Flint Pebbles)

Microcrystalline quartz (SiO2)

Chert (Jasper)

Microcrystalline Silica (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Mookaite Jasper

Silicified Radiolarite (SiO2 with iron impurities)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Banded Agate (specifically Lake Superior Agate style)

Agate (Cryptocrystalline Quartz), SiO2

Jasper

Jasper (Silicon Dioxide, SiO2)

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Banded Agate

Cryptocrystalline Quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Carnelian Agate

Chalcedony (SiO2 with iron oxide impurities)

Yellow Ochre / Limonite

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

Agate Geode

Silicon Dioxide (SiO2)

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Yellow Agate

Agate (Varietal form of Chalcedony/Quartz, SiO2)

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

Carnelian

Chalcedony (Silicon Dioxide, SiO2)

Abalone Shell (Mother of Pearl)

Aragonite (Biogenic Calcium Carbonate, CaCO3)

Carnelian

Silicon Dioxide (SiO2) - variety of Chalcedony

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Pink Dyed Agate

Silicon Dioxide (SiO2) - Variety Agate

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Carnelian

Chalcedony (SiO2) with Iron Oxide impurities

Jasper (Iron-stained Quartzite/Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

Banded Iron Formation (BIF) / Iron Ore

Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)

Red Jasper

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Zebra Jasper

Tetragonal Silicon Dioxide (Quartz) with impurities

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Septarian Nodule (Dragon Stone)

Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)

Ocean Jasper

Orbicular Jasper (Silicon Dioxide with impurities like Hematite and Chlorite, SiO2)