Sedimentary Rock

Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)

Quartz (SiO₂)

man-made composite (lithified equivalent of sedimentary)

Asphalt (Bituminous Concrete)

Bituminous mix / Anthropogenic conglomerate

Zebra Rock (Zebra Stone / Ribbon Stone)

Siltstone with Ferruginous Banding (Primarily Quartz, Kaolinite, and Hematite)

sedimentary

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Mineral, specifically an iron ore

Basalt

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Diorite

Diorite (Intermediate intrusive igneous rock)

Milky Quartz

Silicon Dioxide (SiO2)

Granodiorite

Phaneritic-textured Intrusive Granodiorite

Porphyritic Basalt (River Rock)

Porphyritic Basalt

Calcite

Calcite (Calcium Carbonate, CaCO3)

Mineral Geode/Sedimentary or Volcanic related

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Quartz (likely a weathered/tumbled piece)

Quartz (SiO₂)

Labradorite (tumbled)

Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)

Muscovite Mica

Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2

Basalt

Afanitic Mafic Basalt

Basalt

Mafic volcanic rock (primarily plagioclase, pyroxene, and olivine)

Igneous

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Basalt with Iron Oxidation (Lattice/Veined)

Mafic Volcanic Rock (principally Plagioclase and Pyroxene)

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Vesicular Basalt (Scoria)

Vesicular Basalt

Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)

Carnelian

Carnelian (a variety of Chalcedony, SiO ₂)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)

Silicon Dioxide (SiO2) or Mafic extrusive igneous rock

sedimentary or igneous

Serpentinite (often called Jade or Nephrite substitute)

Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)

metamorphic

Quartzite

Quartzite (SiO2)

Metamorphic

Moonstone

Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8

Schist

Schist (metamorphic rock)

metamorphic

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

sedimentary (silica-rich mineral variety)

Jasper (likely Lake Superior Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartz

Quartz (SiO₂)

Agate

Agate (a cryptocrystalline variety of Quartz, SiO₂)

Basalt with Calcite Veins

Basalt (containing CaCO3 inclusions)

Porphyritic Basalt

Porphyritic Basalt (with Plagioclase phenocrysts)

Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)

Porphyritic Basalt (Mafic Extrusive)

Peach Moonstone

Potassium Aluminum Silicate (KAlSi3O8)

Quartz

Silicon dioxide (SiO2)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)