Sedimentary Rock (Possibly Conglomerate Or Breccia With A Quartz Vein)

Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz

Banded Agate (Onyx variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Mineral (or mineraloid if microcrystalline)

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (specifically Milky/Gray Quartz vein)

Silicon Dioxide (SiO2)

Quartz (Milky or Cloudy Quartz)

Silicon Dioxide (SiO2)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Chalcedony

Chalcedony (a microcrystalline variety of Quartz, SiO2)

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Massive Quartz (Milky or Gray)

Silicon Dioxide (SiO2)

Quartz

Quartz (SiO₂)

Gold-bearing Quartz

Auriferous Quartz (SiO2 with Native Gold inclusion)

Milky Quartz

Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Sedimentary Rock (possibly composed of various minerals)

River Rock / Stream Pebble

Fluvial Clast / Rounded Sedimentary Particle

Quartz (Pebble)

Quartz (SiO₂)

Quartz (Milky/Crystalline)

Silicon Dioxide (SiO2)

Sedimentary or Metamorphic

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Petrified Wood

Silicified Wood (SiO2)

metamorphic

Quartz (Milky or Smoky variety)

Silicon Dioxide (SiO2)

White Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Granitic Pegmatite

Pegmatitic Granite

igneous

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

Quartz Geode/Cluster

Quartz (SiO2)

Sandstone

Quartz Sandstone (predominantly)

Sedimentary

Quartz (Variety of Rough Mineral Specimens)

Silicon Dioxide (SiO2)

Shale (Beach-worn)

Laminated Pelite (primarily clay minerals and quartz)

Dyed Agate (Tumbled)

Silicon Dioxide (SiO2) - stained microcrystalline quartz

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Greenschist (containing Epidote and Quartz)

Greenschist (Epidote-Chlorite-Actinolite Schist)

metamorphic

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)