Sedimentary (Man Made Conglomerate)

Quartz (likely Chalcedony or Chert)

Silicon Dioxide (SiO2)

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Pyrite

Iron Disulfide (FeS2)

Corundum (Ruby variety)

Aluminium oxide (Al2O3)

Diamond (as set in a gold ring)

Carbon (C)

Chalk

Calcium Carbonate (CaCO3)

Chert

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Fossilized Bored Limestone

Limestone with Ichnofossils (Gastrochaenolites or Entobia)

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Chert (Flinty variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Crinoid Fossil Stem Segment

Class Crinoidea (Echinodermata)

Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')

Calcite (Calcium Carbonate, CaCO3)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Brown Variety)

Microcrystalline Quartz (SiO2)

Fossilized Coral (Petoskey-style)

Hexagonaria percarinata (Fossilized Rugose Coral)

Jasper

Silicon Dioxide (SiO2)

Yellow Chert (Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Pyrite

Iron Sulfide (FeS2)

Chert (and Jasper/Chalcedony mixture)

Microcrystalline Quartz (SiO2)

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Banded Sandstone

Arenite with Liesegang banding

White Marble

Recrystallized Calcite Rock (CaCO3)

Diamond

Carbon (C)

Rough Diamond

Native Carbon (C)

Diamond (in a cluster setting)

Crystallized Carbon (C)

Pyrite in Matrix

Iron Sulfide (FeS2)

Sandstone

Arenite (SiO2 principal)

Chert

Microcrystalline quartz (SiO2)

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

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

Calcite (Calcium Carbonate, CaCO3)

Chert (Jasper/Agate variety)

Silicon Dioxide (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert / Green Jasper

Silicon Dioxide (SiO2)