Organic Material (Likely A Fruit Or Berry)

Basalt

Basalt (principally Plagioclase and Pyroxene)

Fossil Sand Dollar (Echinoidea)

Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)

Pink Chert (Brecciated Jasmine/Jasper)

Silicon Dioxide (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Quartzite (River Pebble)

Metamorphic Quartz (SiO2)

Schist

Lepidoblastic Mica Schist

Limestone

Calcium Carbonate (CaCO3)

Beach Pebble (Chert/Quartzite)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (specifically Chert Nodule/Flint)

Chert (Silicon Dioxide, SiO2)

Limestone

Calcium Carbonate (CaCO3)

Rough Diamond

Diamond (pure carbon, C)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Chert (specifically Chalcedony/Flint variant)

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(F,OH)2

Chert (Black Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Septarian Nodule (Dragon Stone)

Septarian Geode (CaCO3 + Mg + Fe)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Quartz-rich Pebble)

Arenite (primarily SiO2)

Turquoise with Pyrite

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O] with Iron Pyrite (FeS2)

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Chert (specifically Gray/Blue Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

Turquoise

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

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Chert (Flint nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

River Rock (Quartzite/Chert conglomerate)

Quartzite (SiO2)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)

Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')

Calcite (Calcium Carbonate, CaCO3)

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)