Sedimentary (Secondary Mineral Formation)

Likely weathered quartz-bearing rock fragment

Provisional identification: quartz-rich sandstone or microcrystalline quartz (SiO₂)

Small weathered mineral/rock fragment

Uncertain from image; possibly quartz-rich sandstone or a feldspar-bearing rock

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chrysocolla in Cuprite

(Cu,Al)2H2Si2O5(OH)4 · nH2O (Chrysocolla) and Cu2O (Cuprite)

Chert (Arrowhead Preform or Flake)

Microcrystalline Quartz (SiO2)

Quartz Geode with Chalcedony

Silicon Dioxide (SiO2) in Geode Form

Agate

Silicon dioxide (SiO2) - variety of chalcedony

Druzy Quartz on Limestone

Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Banded Agate (with possible Chalcedony layers)

Silicon dioxide (SiO2)

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Small rounded tan pebble, likely quartz-rich river stone

Indeterminate; possibly quartz or quartzite (predominantly SiO₂)

Brecciated Agate / Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Sandstone

Arenite (Secondary classification based on grain size)

Geode (unopened)

Calcedony-lined Geode (SiO2)

Limonite (Iron Ore)

FeO(OH)·nH2O

Fossilized Bivalve Shell

Bivalvia (fossil specimen)

Rounded river pebble

Indeterminate lithic clast; likely weathered sandstone or quartz-rich sedimentary rock

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Quartzite Pebble (with iron staining)

Quartzite (SiO2 with ferric oxide impurities)

Jasper

Jasper (Silicon Dioxide, SiO2)

Sandstone Pebble

Sedimentary quartz arenite

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite inclusions

Quartz (likely Chalcedony or Chert)

Silicon Dioxide (SiO2)

Chalcedony

Silicon Dioxide (SiO2)

Native copper-bearing rock (probable copper ore)

Native copper (Cu), likely with cuprite (Cu₂O), malachite (Cu₂CO₃(OH)₂), and iron-oxide matrix

Agate (Common Chalcedony)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Dyed Blue Agate

Silicon Dioxide (SiO2)

Botryoidal Hematite

Hematite (Iron(III) oxide, Fe2O3)

Quartz (Chert/Chalcedony Variety)

Silicon Dioxide (SiO2)

Jasper

Cryptocrystalline Quartz (SiO2)

Chert / Quartz Pebble

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Yellow Calcite

Calcium Carbonate (CaCO3)

Limonite (with Pyrite)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Fossilized tooth or jaw fragment (likely fish or reptile)

Indeterminate vertebrate bone/tooth; mineralized hydroxyapatite, commonly Ca₅(PO₄)₃(OH)

Agate Nodules

Cryptocrystalline Quartz (SiO2)

Fossilized bone

Petrified bone; commonly fossil vertebrate bone composed largely of hydroxyapatite and silica/calcite replacement minerals