Sedimentary Or Igneous Fragment

Quartz Geode Fragment

Silicon Dioxide (SiO2) in a Sedimentary Host

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz

Quartz (Silicon Dioxide - SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz

Silicon Dioxide (SiO2)

igneous, sedimentary, or metamorphic (mineral-based)

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

Amethyst (Geode Fragment)

Silicon Dioxide (SiO2 with iron impurities)

Quartz (Clear/White)

Silicon Dioxide (SiO2)

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Shale

Laminated Mudstone

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

Quartz (SiO₂)

Quartz (Crystal Point/Fragment)

Silicon Dioxide (SiO2)

Granitic Sand

Detrital sediment (predominantly Quartz, Feldspar, and Mica)

Oolitic Limestone

Oolitic Carbonate (CaCO3)

Oolitic Limestone

Oolitic Limestone (Calcium Carbonate, CaCO3)

Anthropogenic material (Man-made sedimentary mimic)

Terracotta (Man-made ceramic brick fragment)

Baked clay / High-iron ceramic (Silicate-based ceramic)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Potassium aluminum silicate (KAlSi3O8)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Conglomerate

Polymictic Conglomerate

Quartz (likely Jasper or Chert variety)

Quartz (SiO₂)

Sea Shell (Fighting Conch Fragment)

Calcium Carbonate (CaCO3) - Strombus alatus fragment

sedimentary (biogenic)

Greenstone

Metamorphosed Mafic Igneous Rock

metamorphic

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (lithic wacke/conglomerate mix)

Clastic Sedimentary Rock (SiO2 with lithic fragments)

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

Quartz (likely Milky Quartz)

Quartz (SiO₂ - Silicon Dioxide)

Sandstone (likely Fossiliferous)

Arenite / Sedimentum arenaceum

Concretion

Various mineral compositions, typically carbonate or iron oxide cemented sediment

Sedimentary

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Oolite (Ooids)

Oolitic Limestone (Principal mineral: Calcite, CaCO3)

Oolitic Limestone

Oolite (Sedimentary rock composed of CaCO3)

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)