Sedimentary (Chemically Precipitated Mineral)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz with Limonite/Goethite staining)

Halite (Rock Salt)

Halite (NaCl)

Chert / Jasper

Silicon Dioxide (SiO2)

Chert (or Flint)

Chert (SiO2)

Pyrite Concretion

Iron Sulfide (FeS2) in Sedimentary Matrix

Oolitic Limestone

Oolite (Sedimentary rock composed of CaCO3)

Black Limestone with Calcite Veining

Bituminous Limestone (CaCO3 with Organic Carbon inclusions)

Dyed Blue Agate

Chalcedony (Silicon Dioxide / SiO2)

Dyed Agate Slice

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Quartz Pebble (with potential iron inclusions)

Silicon Dioxide (SiO2)

Blue Howlite (Dyed)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Granite (likely biotite granite or granodiorite)

Coarse-grained granitoid composed mainly of quartz, feldspar, and dark biotite/hornblende

Chert (River Pebble)

Silicon Dioxide (SiO2)

Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)

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

Limonite (with Goethite/Ironstone)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Weathered Sedimentary Rock with Liesegang Rings

Sandstone or Siltstone with Iron Oxide Banding

Bumble Bee Jasper

Calcite-bearing Volcanic Tuff (not a true Jasper)

Chert (Nodule)

Chert (composition: SiO2)

Quartz (likely a form of massive or vein quartz)

Quartz (SiO₂)

Quartz (Milky or Smoky Quartz)

Silicon Dioxide (SiO2)

Weathered metamorphic rock, likely gneiss or schist

Indeterminate foliated silicate rock; commonly quartz–feldspar–mica assemblage

Quartz (Specifically Clear to Smoky Quartz point)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Chert (Flint/Jasper)

Silicon Dioxide (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper based on color)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Sandstone (with Liesegang rings)

Quartz Sandstone (SiO2 with Fe-oxide staining)

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial purple dye

Hematite Pebble

Iron(III) oxide (Fe2O3)

Orange Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite

Calcium Carbonate (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Jasper

Microcrystalline Quartz (SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Tumbled Jasper and Tiger's Eye

Silicon Dioxide (SiO2) with iron oxide inclusions

Chalcedony (Carnelian Agate)

Cryptocrystalline quartz (SiO2) with Iron Oxide inclusions