Sedimentary (Silica Rich Mineral Variety)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Clear Quartz crystals on a Matrix base (Geode fragment)

Silicon Dioxide (SiO2)

Banded Agate (Crazy Lace/Mexican Agate Variety)

Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite inclusions

Chrysoprase

Chalcedony (cryptocrystalline SiO2 variety)

Rose Quartz

Rose Quartz (SiO₂)

Lake Superior Agate

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone

Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)

Chert (specifically tan/pink variety)

Silicon Dioxide (SiO2)

Chert (specifically Brown Chert or Jasper)

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Sandstone (Pebble)

Arenite (primarily SiO2)

Quartz Vein in Host Rock (Gossanous Matrtix)

Silicon Dioxide (SiO2) with iron oxides (Limonite/Hematite)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Black Tourmaline

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)

Quartz Crystal (specifically a small Clear Quartz point)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Schist

Schist (various mineralogical compositions including mica, chlorite, talc, etc.)

Olivine (likely Peridot variety)

Olivine Mineral Group (specifically Forsterite-Fayalite solid solution series); Chemical formula: (Mg,Fe)2SiO4

Hematite

Hematite (Fe2O3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Quartz Geode

Silicon Dioxide (SiO2)

Banded Agate

Chalcedony (Silicon Dioxide, SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Granite

Granite (Silicic Plutonic Rock)

Sandstone (Ferruginous)

Arenite (with Hematite/Limonite cement)

Raw Emerald in Schist Matrix

Beryl (Be3Al2Si6O18) in Mica Schist

Agate (Chalcedony)

Cryptocrystalline Silica or Silicon Dioxide (SiO2)

Fancy Jasper (Multicolor Agate/Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Agate Geode

Cryptocrystalline Quartz (SiO2)

Red Sandstone

Arenite (high iron oxide content)

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Orbicular Granite (specifically Mustard or Yellow Tonalite/Granodiorite)

Orbicular Quartz Diorite / Tonalite

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Jasper

Silicon dioxide (SiO2) with iron oxide and clay inclusions

Chert (with Quartz vein/coating)

Microcrystalline Quartz (SiO2)