Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Snowflake Obsidian (Flower Jasper variant)

Vitreous volcanic silicate with cristobalite inclusions

Vesicular Basalt (Scoria)

Basalt (Extrusive Igneous Rock)

Ferruginous Sandstone (Ironstone)

Arenite with Limonite/Goethite cement

Chert (and Flint variant)

Microcrystalline Quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Chert (Flint variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

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

Jasper, microcrystalline quartz (SiO₂)

River Chalcedony / Agate

Chalcedony (Silicon Dioxide, SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gneiss (specifically Granite Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Quartz Geode (partially formed/chalcedony with iron staining)

Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides

Amygdaloidal Basalt

Basalt with Secondary Mineral Infillings

Jasper

Silicon dioxide (SiO2)

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with impurities of Iron Oxide

Chert (Red/Brown Variety)

Microcrystalline quartz (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)

Chert (and Flint)

Chert (SiO2)

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)

Yellow Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide, SiO2)

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Jasper (specifically Red Jasper or Iron-stained Chert)

Silicon dioxide (SiO2) with iron oxide inclusions

Limestone (Weathered Aggregate)

Sedimentary Carbonate Rock (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Quartzite (clastic/metamorphic subtype)

Quartzite (primarily Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Banded Agate (Onyx variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert / Flint

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Quartzite

Quartzite (SiO2)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

Basalt with Quartz Vein

Mafic Igneous Rock (SiO2 filling)

Pebble or Cobble (likely composed of sandstone or conglomerate)

Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)