Anthropogenic Specimen (Man Made)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Nodule)

SiO2 (Microcrystalline Quartz)

Chert (Field Stone)

Chert (Silicon Dioxide, SiO2)

Diabase (also known as Dolerite)

Diabase

Quartzite Pebble

Quartzite (SiO2 with minor impurities)

Granite

Granite (Phaneritic igneous rock)

Banded Jasper with Hematite or Quartz

Silicon Dioxide (SiO2) with impurities

Limestone (specifically Marl or Chalk)

Calcium Carbonate (CaCO3)

Granite

Phaneritic Felsic Intrusive Igneous Rock

Chalcedony (Agate/Carnelian type)

Silicon Dioxide (SiO2)

Coral Fossil (Favosites)

Favosites (Extinct genus of tabulate corals)

Chalcedony (Agate Nodules)

Silicon Dioxide (SiO2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (likely Chalcedony or Quartzite)

Silicon Dioxide (SiO2)

Turquenite (Dyed Howlite)

Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Quartzite Pebbler

Quartzite (primarily SiO2)

Quartz (Smoky/Milky variant)

Silicon Dioxide (SiO2)

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

Granite (weathered cobble)

Granite

Quartz (possibly Citrine or Smoky Quartz variety)

Silicon Dioxide (SiO2)

Diorite (River Pebble)

Intermediate plutonic igneous rock

Ocean Jasper

Orbicular Jasper (Silicon Dioxide with impurities like Hematite and Chlorite, SiO2)

Quartz (Milky or Citrine-tinted)

Silicon Dioxide (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Granite (Alkali-feldspar Granite)

Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Sandstone (Green/Yellow Siltstone variant)

Arenite or Siltstone (primarily SiO2 with mineral staining)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2 with minor Fe2O3)

Sandstone (Pebble)

Arenite (primarily SiO2)

Granite (Pink/Red variety)

Phaneritic Felsic Intrusive Igneous Rock (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Sandstone

Arenite (SiO2 based clastic rock)

Basalt (Vesicular and Ropey)

Vesicular Basalt / Pahoehoe Basalt

Agate

Silicon Dioxide / Cryptocrystalline Quartz (SiO2)

Basalt (Vesicular/Scoriaceous)

Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)

Chert (River Pebble)

Chert (Microcrystalline Quartz, SiO2)

Yellow Quartzite (River Pebble)

Quartzite (primarily SiO2)

Chert / Red Jasper

Microcrystalline Quartz (SiO2)

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Obsidian

Obsidian (Volcanic Glass)

Porphyritic Rhyolite

Porphyritic Rhyolite (compositionally similar to granite)