Anthropogenic (Man Made Material)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Jasper (Cream/Yellow variety)

Jasper (Microcrystalline Quartz, SiO2)

Polygenetic Conglomerate (Puddingstone)

Conglomerate (SiO2 matrix with mixed clasts)

Sandstone

Arenite (SiO2 predominantly)

Quartz (Milky and Smoky variety)

Silicon Dioxide (SiO2)

Sandstone (Quartzite Pebble)

Arenite (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Sandstone (likely Arkosic or Quartzose)

Sandstone (SiO2 dominated)

Quartzite

Quartzite (primarily SiO2)

Sandstone

Arenite (SiO2 primarily)

Sandstone (Water-worn Cobble)

Arenite (variable composition, primarily SiO2)

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Marble

Recrystallized Calcite (CaCO3)

Green Common Opal

Hydrated Silica (SiO2·nH2O)

Milky Quartz

Silicon Dioxide (SiO2)

Septarian Nodule (Galt)

Calcareous concretion / Septarian concretion

Sandstone

Arenite (SiO2 based)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Greenschist

Greenschist (Chlorite Schist)

Sandstone

Arenite (SiO2 based with quartz grains)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Limestone

Calcium carbonate (CaCO3)

Sandstone

Clastic Sedimentary Rock (composed of SiO2 grains)

Lepidolite on Pegmatite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2) in Granitic Pegmatite

Sandstone

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Sandstone (Quartzose)

Arenite (SiO2 based)

Sandstone (with potential iron-oxide staining)

Arenite (primarily SiO2)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Shale

Laminated Mudstone

Porphyritic Basalt (Chinese Writing Stone or Flower Stone)

Porphyritic Basalt / Porphyry

Quartz Pebble (with probable inclusions or staining)

Quartz (Silicon Dioxide - SiO2)

Snowflake Obsidian

Obsidian (volcanic glass) with Cristobalite inclusions

Quartz / Common Agate

Silicon Dioxide (SiO2)

Conglomerate

Clastic Sedimentary (Conglomerate)

Thunderegg (specifically a Jasper/Agate-filled Geode nodule)

Silicon Dioxide (SiO2) within Rhyolitic Matrix

Fossiliferous Limestone

Fossiliferous Calclutite / Bio-calcarenite (CaCO3)

Sandstone

Arenite (composed primarily of SiO2)