Sedimentary Or Igneous Fragment

Quartz-rich rock fragment, possibly granite or quartzite

Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining

Milky quartz

Quartz (silicon dioxide, SiO₂)

River Stone (Chalcedony/Jasper variety)

Microcrystalline Quartz (SiO2)

Basalt (Road Gravel)

Basalt (Mafic Extrusive Igneous Rock)

Quartz (Druzy or Geode fragment)

Silicon Dioxide (SiO2)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Chert (Arrowhead Fragment)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Quartz fragment

Silicon Dioxide (SiO2)

Fossil Shark Tooth Fragment

Elasmobranchii dentition (fragment)

Granite or Quartzite fragment

Granite / Quartzite

Basalt Xenolith in Matrix

Basaltic Mafic Xenolith / Ultra-mafic Inclusion

Unidentified weathered rock, possibly quartz-bearing granite or rhyolite

Indeterminate; likely quartz–feldspar-rich silicate rock

Iron Meteorite (Campo del Cielo)

Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)

Fossilized Echinoid Fragment (Calycinal/Boss Fossil)

Echinodermata fossil fragment

Quartz (Milky/Smoky Crystal fragment)

Silicon Dioxide (SiO2)

Weathered granite (likely with accessory quartz)

Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende

Quartz Pebble

Silicon Dioxide (SiO2)

Coquina or Fossilized Shell Fragment

Calcium Carbonate (CaCO3) / Biogenic Limestone

Weathered sandstone fragment

Sandstone, primarily quartz (SiO₂) with feldspar and iron-oxide cement

Citrine Geode Fragment

Silicon Dioxide (SiO2) with iron impurities

Quartz (Milky or Cloudy)

Silicon Dioxide (SiO2)

Chert (specifically Yellow Jasper variety)

Silicon Dioxide (SiO2)

Ironstone Concretion

Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)

Limestone Fragment

Sedimentary rock (primarily Calcium Carbonate, CaCO3)

Tumbled brecciated jasper

Silica-rich microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz-rich vein rock, likely milky quartz in weathered host rock

Milky quartz (SiO₂), probably with weathered feldspar and iron-oxide staining

Milky Quartz

Silicon Dioxide (SiO2)

Weathered iron-rich rock, possibly basalt or ironstone

Indeterminate; likely Fe-oxide-bearing basaltic rock (commonly magnetite/hematite in a silicate matrix)

Diorite with Xenolith

Phaneritic Intermediate Plutonic Rock

Granite Pebble

Granite (composed of Quartz, Feldspar, and Mica)

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Fossiliferous Shale

Laminated Mudrock with plant fossils

Likely tumbled sandstone or limestone

Quartz-rich sandstone (possibly calcarenite/limestone)

Weathered sandstone or quartz-rich sedimentary pebble

Indeterminate lithic fragment; likely quartz arenite (sandstone)

Chalcedony (Blue Dragon/Gray Chalcedony)

Silicon Dioxide (SiO₂)

Quartz (Microcrystalline variety)

Silicon Dioxide (SiO2)

Seashell Fragment (Aragonite/Calcite)

Calcium Carbonate (CaCO3) - Shell fragment

Milky Quartz

Silicon Dioxide (SiO2)

Folded Schist / Gneiss (Metamorphic Rock)

Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)