Not A Rock

Amber (Rough Baltics/Beach Specimen)

Succinicum (Organic Gemstone - Fossilized Resin)

Red Sandstone (Hematitic)

Clastic sedimentary rock (SiO2 with Fe2O3 inclusions)

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Basalt (River Pebble)

Basalt (dominated by Plagioclase Feldspar and Pyroxene)

Vesicular Basalt (Scoria)

Mafic extrusive igneous rock (primarily Plagioclase Feldspar and Pyroxene)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide - SiO2)

Porphyritic Basalt (Amygdaloidal)

Porphyritic Mafic Volcanic Rock (Amygdaloidal Basalt)

Diorite (Dalmatian Stone variant)

Phaneritic Plutonic Igneous Rock (Medium to Fine-grained Diorite)

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Orange Quartzite (River Pebble)

Quartzite (SiO2 with iron oxide inclusions)

Jasper and Quartz conglomerate (River Rock)

Silicon Dioxide (SiO2) - Chalcedony and Quartz variety

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Granite (specifically Pink or Alkali Feldspar Granite)

Felsic Plutonic Rock (primarily SiO2 with KAlSi3O8)

Sandstone (likely Navajo Sandstone)

Arenite (primarily SiO2)

Granite Pebble

Felsic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)

Granite Pebble (Pink Granite)

Phaneritic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of iron oxide)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Goethite/Hematite shell with Sandstone core)

Carnelian Agate

Chalcedony (Silicon Dioxide, SiO2) with Iron Oxide impurities

Flower Agate

Chalcedony (SiO2) with Scolecite/Opaque inclusions

Leopard Skin Jasper

Silicon Dioxide (SiO2) with impurities

Moqui Marble (Iron Concretion)

Iron Oxide Concretion (Goethite/Hematite Cemented Sandstone)

Limonite (often after Hematite or Goethite)

Limonite (FeO(OH)·nH2O)

Quartz (River Stone)

Silicon Dioxide (SiO2)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Wonderstone (Liesegang Sandstone)

Silicified Sandstone with Liesegang Rings (SiO2 + FeO(OH))

Quartzite

Metamorphic Quartz (SiO2)

Quartzite Pebbles (River Stones)

Quartzite (primarily Silicon Dioxide, SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide staining/cementing)

Rough Quartz in Pegmatite Matrix

Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Septarian Nodule

Septarian concretion (Complex mixture of Siderite/Limestone, Calcite, and Aragonite)

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 principal composition)