Sedimentary Rock (Specifically A Chemical Sedimentary Rock, Or A Chert If Considered Purely Mineral Aggregate)

Chert (Green variety)

Microcrystalline Opaline/Quartz (SiO2)

Chert (River Cobble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Limestone

Calcium Carbonate (CaCO3)

Quartz (Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2)

Chert / Pink Chert

Silicon Dioxide (SiO2)

Chert (Jasper/Agate variety)

Microcrystalline quartz (SiO2)

Red Chert (Jasper)

Silicon Dioxide (SiO2)

Limestone

Sedimentary Limestone (Calcium Carbonate, CaCO3)

Chert (Jasper/Agate)

Silicon Dioxide (SiO2)

Breciated Chert

Brecciated Chert (Microcrystalline Quartz, SiO2)

Chert (Nodular)

Chert (Microcrystalline Quartz, SiO2)

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone

Limestone (Calcium Carbonate: CaCO3)

Banded Chert (River Pebble)

Microcrystalline Quartz (SiO2)

White Marble

Recrystallized Calcite (CaCO3)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Ironstone Concretion (Coprolite-like)

Goethite/Hematite Siderite Spheroid (FeCO3 or FeO(OH))

Concrete Fragment

Hardened Portland cement and mineral aggregate

River Rocks (Black)

Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts

Banded Agate (specifically Carnelian Agate)

Silicon Dioxide (SiO2)

Chert (specifically Zebra Chert/Flint)

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Raw Green Jasper

Silicon Dioxide (SiO2) with iron silicate inclusions

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Green Chalcedony (likely Green Agate or Chrysoprase)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Jasper focus)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Limestone

Sedimentary Calcite (CaCO3)

Jasper-Quartz Conglomerate / Chert

Siliceous Sedimentary Rock (SiO2)

Banded Sandstone

Arenite (with iron oxide banding)

Bauxite

Al2O3·2H2O (principally composed of gibbsite, boehmite, and diaspore)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Halite

Halite (NaCl)

Chalcedony (Botryoidal Agate vein)

Chalcedony (Microcrystalline Quartz) - SiO2

Himalayan Pink Salt (Halite)

Halite (Sodium Chloride, NaCl)

Sandstone Concretion (Omar or Nut Rock)

Sedimentary Concretion (specifically an 'Omarolluk' or Omar)