Rock

Vesicular Basalt (Scoria)

Basalt with vesicular texture

Basalt Scoria

Aphanitic Vesicular Basalt

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Basalt

Mafic extrusive igneous rock

Vesicular Basalt

Basalt (principally Plagioclase and Pyroxene)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

River Pebbles / Mudstone

Sedimentary Rock / Silty Claystone

Quartz Geode Cluster (Iron-stained Quartz)

Silicon Dioxide (SiO2)

Yellow Chalcedony (Carnelian / Agate Pebbles)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Desert Rose (Gypsum / Barite Rose)

Hydrated Calcium Sulfate (CaSO4·2H2O) / Barium Sulfate (BaSO4)

Sandstone

Sandstone (SiO2 predominant)

Sandstone Pebble

Sandstone (Siliciclastic Sedimentary Rock)

Quartz pebble (Quartzite / Chert)

Silicon Dioxide (SiO2)

Beach Pebble (Basalt / Greywacke Gravel)

Mafic Volcanic Rock (Basalt)

Quartz Pebble

Silicon Dioxide (SiO2)

Diorite (River Cobble)

Intermediate phaneritic igneous rock

Sandstone Pebble

Ferruginous Sandstone (SiO2 with Fe2O3)

Green Quartz (Prasiolite / Chlorite-Included Quartz Pebble)

Silicon Dioxide (SiO2) with micro-inclusions

Granite Pebble

Granite

Diorite (or Gabbro/Gneiss stream pebble)

Diorite

Quartz (Milky / Clear Quartz Fragment)

Silicon Dioxide (SiO2)

Red Sandstone (River Cobble)

Quartz Arenite / Ferruginous Sandstone

Banded Chert Pebble

Silicon Dioxide (SiO2)

Beach Pebble / Agate-bearing Chert Pebble

Microcrystalline Quartz (SiO2) with Inclusion Minerals

River Pebble (Quartzite / Sandstone)

SiO2 (Quartz-rich sedimentary/metamorphic rock)

Beach Pebble Quartzite / Chalcedony Pebble

Silicon Dioxide (SiO2)

Porphyritic Basalt (or Porfido / Porphyry Beach Pebble)

Porphyritic Basalt / Andesite

Greenstone / Greywacke

Metagraywacke (contains Chlorite and Epidote)

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Gneiss

Gneiss

Scoria

Scoria (vesicular basalt-andesite)

Amygdaloidal Basalt with Quartz

Basalt with Secondary Mineral Infilling

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (mostly SiO2)

Sandstone (lithic wake or graywacke)

Clastic sedimentary rock (primarily quartz and lithic fragments)

Jasper River Stone

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (primarily SiO2)

Greenstone with Magnetite Veins

Metabasalt (Greenstone)

Gray River Pebble (likely Limestone or Siltstone)

Sedimentary Rock (Calcium Carbonate or Siliciclastic)

Blue Quartzite (Dyed)

Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)