Marble

Chert (Pink Jasper)

Microcrystalline Quartz (SiO2)

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert (Field Stone)

Chert (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone (likely Arkosic or Quartzose)

Arenite (SiO2 based with mineral inclusions)

New Jade (Serpentine)

Antigorite / Serpentine Group (Mg3Si2O5(OH)4)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Chert (specifically Flint)

Microcrystalline Quartz (SiO2)

Chert (containing Flint nodules)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Diamond (in a Gold Jewelry Setting)

Carbon (C)

Sandstone

Arenite (primarily Quartz, SiO2)

Green Chert (Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Blue Aragonite

Aragonite (Calcium Carbonate, CaCO3)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Chert (Flint variety)

Chert (Cryptocrystalline Quartz, SiO2)

Peridot (Gem-quality Olivine)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Chert Nodule

Microcrystalline Quartz (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Peridot (likely, given the color and bead form)

Olivine, variety Peridot (Mg,Fe)2SiO4

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Chert (River Pebble)

Chert (Microcrystalline Quartz, SiO2)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Diamond

Diamond (pure Carbon, C)

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Serpentinite (often containing Jadeite/Nephrite)

Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4

Chert (often called Jasper in this color variety)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant)

Silicon Dioxide (SiO2)

Chert (Flint/Chalcedony)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Coquina / Shell Limestone)

CaCO3 (Calcium Carbonate)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)

Limestone (Weathered Aggregate)

Sedimentary Carbonate Rock (CaCO3)

Chert (Chalcedony)

Silicon Dioxide (SiO2)

Limestone (River Pebble)

Sedimentary Calcium Carbonate (CaCO3)

Pyrope Garnet (Bohemian Garnets)

Pyrope (from the group Mg3Al2(SiO4)3)

Diamond

C (Carbon)

Chert (Flint/Jasper variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone

Calcareous sedimentary rock (primarily Calcium Carbonate, CaCO3)

Diamond

Carbon (C)

Shiva Eye Shell (Operculum)

Calcium Carbonate (Aragonite), CaCO3