Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)

Chert (specifically Chalcedony/Flint variant)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically a Chert Nodule or Flint)

Cryptocrystalline Quartz (SiO2)

Chert (specifically Chalcedony or Flint variation)

Microcrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint variety)

Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (specifically Jasper/Carnelian variety)

Microcrystalline quartz (SiO2)

Chert (specifically Flint or Common Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper (specifically Fancy Jasper or Bloodstone variety)

Silicon Dioxide (SiO2) with impurities (Iron oxides/silicates)

Chert (specifically Flint or Common Chert)

Silicon Dioxide (SiO2)

Jasper (specifically Yellow and Red Jasper/Chert)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Jasper (specifically Picture Jasper or Landscape Jasper)

Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz

Basalt with Quartz Veins

Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)

Basalt (Weathered/River worn)

Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Pumice

Vesicular volcanic glass (primarily Alumino-silicates)

Pumice

Pumice (Volcanic glass with vesicular texture)

Pumice

Pumice (a highly vesicular volcanic rock)

Quartz (specifically Milky or Clear Quartz)

Silicon Dioxide (SiO2)

Lava Rock (Scoria)

Scoria (Vesicular Basalt)

Quartz Pebble

Silicon Dioxide (SiO2)

Andesite

Andesite (Intermediate Volcanic Rock)

Quartz

Quartz (SiO₂)

Limestone

Calcium Carbonate (CaCO3)

Andesite

Andesite (Intermediate Extrusive Volcanic Rock)

Basalt

Basalt (Extrusive Mafic Igneous Rock)

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

Conglomerate

Conglomerate (SiO2 matrix with various inclusions)

Basalt

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Hematite

Hematite (Fe2O3)

Basalt

Extrusive mafic rock (Basalt)

Crushed Limestone

Calcium Carbonate (CaCO3)

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Basalt with Desert Varnish

Mafic Volcanic Rock (Fe/Mg rich Silicate)

Moss Agate

SiO2 (Silicon Dioxide) with dendritic inclusions

Sandstone (Quartz Sandstone)

Arenite (primarily SiO2)

Basalt

Basalt (Mafic volcanic rock)

Basalt

Extrusive mafic igneous rock

Basalt

Basalt (Mafic volcanic rock)

Fossil Coral (Petoskey Stone or Favosites)

Favosites (specifically Hexagonaria percarinata if silica-replaced Michigan type)

Basalt (Road Aggregate / Crushed Stone)

Aphanitic Mafic Igneous Rock

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Sandstone

Arenite (SiO2 based with various mineral cements)