Organic Material (Likely A Fruit Or Berry)

Chert (Flint variety)

Microcrystalline context of Quartz (SiO2)

Chert (Cherty Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limonite (Iron-rich Siltstone / Sandstone base)

Hydrous ferric oxide mixture (FeO(OH)·nH2O)

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Nuummite

Nuummite (Ortho-amphibole rock, primarily Anthophyllite and Gedrite)

Granite Pebble

Granite; primarily composed of Quartz (SiO2), Feldspar (KAlSi3O8), and Mica

Biotite (Mica)

Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2

Chert (varietal: Flint/River Pebble)

Cryptocrystalline Quartz (SiO2)

Chert (Field Stone)

Chert (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper/Agatized Chert)

Microcrystalline Quartz (SiO2)

Chert (with Limestone matrix)

Microcrystalline Quartz (SiO2)

Chert (often referred to as Flint or Jasper)

Chalcedony (SiO2) - Silicon Dioxide

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Limonite (Ironstone)

Limonite (FeO(OH)·nH2O)

Chert (Smooth River Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) / Microcrystalline Quartz

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sodalite

Sodalite: Na8(Al6Si6O24)Cl2

Chert (specifically Flint)

Chert (SiO2)

Limonite (Gozzany Iron)

Limonite (FeO(OH)·nH2O)

Laterite

Laterite (Ferricrete)

Diamond

Diamond (pure carbon; C)

Chert (often called Flint or Jasper based on color)

Microcrystalline Silica (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

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

Calcite (Calcium Carbonate, CaCO3)

Chert (specifically Flint)

Microcrystalline Quartz (SiO2)

Concrete / Conglomerate (Man-made)

Artificial Conglomerate (Cementitious Composite)

Chert (Common Opal variant)

Silicon Dioxide (SiO2)

Chert / Flint

Chert (Cryptocrystalline Silica, SiO2)

Chert (and Flint variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Quartzite pebble

Quartzite (primarily SiO2)

Granite

Granite (Felsic Plutonic Rock)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert (Basanite / Flint)

Microcrystalline Quartz (SiO2)