Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Banded Agate

Chalcedony (Silicon Dioxide, SiO2)

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Quartz (Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Quartz (Milky/Crystalline variety)

Silicon Dioxide (SiO2)

Ironstone Concretion (Moqui Marble)

Hematite/Goethite Concretion (Fe2O3 / FeO(OH))

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2) crystal conglomerate

Chert / Flint Conglomerate

Silicified Sedimentary Breccia (primarily SiO2)

Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)

Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)

Chert with Quartz Veining

Silicon Dioxide (SiO2)

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Quartz (Peach/Orange variety)

Silicon Dioxide (SiO2)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Quartzite (Yellow/Tan Quartz Cobble)

Metamorphosed Quartz Sandstone (SiO2)

Quartz-veined Siltstone

Siltstone with Quartz (SiO2) veins

Quartz

Silicon Dioxide (SiO2)

Quartz (Float/Abraded)

Quartz (SiO₂)

Native Sulfur

Sulfur (S8)

Ferruginous Sandstone (Red Sandstone)

Arenite with Hematite/Limonite cement

Quartzite (specifically a river-worn cobble)

Quartzite (primarily Silicon Dioxide, SiO2)

Turquoise

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

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

Limonite Concretion

Limonite (FeO(OH)·nH2O)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Chert Nodule (Commonly known as a Flint or River Cobble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Sandstone (Ferruginous)

Arenite (with high iron oxide content)

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides (Goethite)

Quartz

Silicon Dioxide (SiO2)

Chrysoprase

Silicon dioxide (SiO2) with nickel impurities

Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

River Quartzite Siltstone

Quartz-rich Meta-siltstone (SiO2 dominated)

Chert (often called Jasper in this color variety)

Microcrystalline Quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone (Quartzose Sandstone Pebble)

Arenite (primarily SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz (Milky or Druzy Quartz)

Silicon Dioxide (SiO2)

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)

Chert (with Limonite staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)

Basalt River Stone

Basalt (Aphanitic Mafic Volcanic Rock)