Sedimentary Or Igneous Fragment

Rounded pink granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed primarily of quartz, feldspar, and minor mica or amphibole

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Weathered sandstone or tuff fragment

Likely quartz-rich sandstone (SiO₂) or porous volcanic tuff; exact identification requires testing

Weathered sandstone or limestone fragment

Indeterminate clastic carbonate/siliciclastic rock; likely quartz-rich sandstone or porous limestone

Sandstone (Greywacke)

Arenite / Wacke (Mainly SiO2 with various lithic fragments)

Chert (potentially worked flint)

Cryptocrystalline microcrystalline quartz (SiO2)

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz Druzy Geode Fragment

Silicon Dioxide (SiO2)

Weathered sandstone or iron-stained quartz-rich river cobble

Quartz-rich sandstone; predominantly SiO₂ with iron-oxide staining

Oolitic Limestone

Oosparite / Oolitic Calcarenite (CaCO3)

Chert (variously identified as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Dark flint or chert fragment

Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular

Weathered flint or chert fragment

Microcrystalline quartz (SiO₂), likely chert/flint

Septarian Nodule (Micro-fragment)

Septarian Nodule / Concretion (CaCO3 + CaMg(CO3)2 + Quartz)

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Weathered granite or granitic gneiss slab

Granitic rock, chiefly quartz, feldspar, and mica; exact identification is uncertain from the photograph

Conglomerate

Conglomerate (clastic sedimentary rock)

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3)

Weathered iron-rich sandstone or lateritic rock

Ferruginous sandstone/laterite; chiefly quartz (SiO₂) with iron oxides such as hematite and goethite

Weathered iron-rich sandstone or laterite fragment

Ferruginous sandstone, chiefly quartz (SiO₂) cemented or stained by iron oxides/hydroxides

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Honey calcite (orange calcite)

Calcite, calcium carbonate (CaCO₃)

Fossiliferous Limestone (Coquina / Shell Conglomerate)

Bioclastic Limestone (composed primarily of CaCO3)

Granite

Intrusive Igneous Rock

Banded Iron Formation (Fragment)

Banded Iron Formation (BIF)

Chert / Flint Nodular Fragment

Microcrystalline quartz (SiO2)

Weathered sandstone or arkose fragment

Quartz-rich clastic sedimentary rock; likely sandstone/arkose (dominantly SiO₂ quartz with feldspar and lithic grains)

Desert Rose Fragment (Atypical) / Weathered Chert

Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy

Fossiliferous Limestone

Biogenic Sedimentary Rock / CaCO3 with fossil fragments

Coquina

Biogenic Limestone (Coquina)

Concrete Fragment

Hardened Portland Cement Composite

Limestone with Fossil

Sedimentary limestone, calcium carbonate (CaCO3)

Fossiliferous Limestone

Biogenic Sedimentary Rock (primarily CaCO3 with fossil fragments)

River Pebble

Siliceous rock fragment / Quartzite / Sandstone pebble

Pebble

Lithic fragment (Quartzite or general rock pebble)

Likely quartz-rich mineral fragment

Quartz (SiO₂), possibly iron-stained or included quartz

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

Conglomerate

Pebble Conglomerate / Clastic Sedimentary Rock

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

Quartz (SiO₂)