Sedimentary Rock (Altered)

Banded Iron Formation (BIF)

Banded Iron Formation

Coal (most likely Bituminous or Anthracite)

Coal (primarily composed of carbon with varying amounts of other elements)

Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)

Jasper, microcrystalline quartz (SiO₂)

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2)

Graphite-veined Quartzite

Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)

Jasper River Pebble

Silicon Dioxide (SiO2)

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2) crystal conglomerate

Gneiss (specifically a granitic gneiss cobble)

Gneiss (high-grade regional metamorphic rock)

Asphalt

Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Red Jasper

Jasper (a variety of Quartz, SiO2)

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Quartz (likely a weathered/tumbled piece)

Quartz (SiO₂)

Labradorite (tumbled)

Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)

Muscovite Mica

Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2

Gneiss (specifically a Banded Gneiss pebble)

Gneiss (High-grade Regional Metamorphic Rock)

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Tiger's Eye

Quartz (SiO2) with fibrous inclusions of Altered Crocidolite

Carnelian

Carnelian (a variety of Chalcedony, SiO ₂)

Diamond Drill Core (Greenschist and Quartzite)

Chlorite Schist / Meta-quartzite (Metamorphic Rock Core Sample)

Exposed Aggregate Concrete (Pea Gravel)

Concrete with Siliceous Alluvial Gravels

Grey Slate

Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)

Dolomite

Dolomite (CaMg(CO3)2)

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)

Lapis Lazuli

Na8[Al6Si6O24]S2

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Quartz

Quartz (SiO₂)

Agate

Agate (a cryptocrystalline variety of Quartz, SiO₂)

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Chert (Yellow Jasper/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Hagstone/Gasket Rock variant)

Chert (SiO2)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)

Gneiss

Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

Quartz (Float/Abraded)

Quartz (SiO₂)

Red Jasper (beads)

SiO₂ (Silicon Dioxide)

Chert (Flint)

Chert (predominantly SiO₂ - silicon dioxide)