Quartz

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Mineral

Glauconitic Sandstone (Greensand)

Glauconitic quartz wacke or arenite

Herkimer Diamond

Double-Terminated Quartz (SiO2)

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Geode (Unopened)

Silicon Dioxide (SiO2) in sedimentary vugs

Green Aventurine

Aventurine Quartz (SiO2 with inclusions)

Metamorphic, likely Sedimentary with Quartz veins

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Milky Quartz

Silicon Dioxide (SiO2)

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Yellow Aventurine (or Citrine-colored Quartz)

Silicon Dioxide (SiO2) with inclusions

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Granitoid Pebble (Graphic Granite/Pegmatite)

Pegmatitic Granite with Quartz and Orthoclase

igneous

Quartz (Iron-stained)

Silicon Dioxide (SiO2) with hematite/limonite inclusions

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Mineral

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Quartz nodule (River pebble)

Silicon Dioxide (SiO2)

Yellow Quartz / Quartzite Pebble

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Amazonite

K(AlSi3O8) - Microcline variant

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Banded Chert

Sedimentary Cryptocrystalline Quartz (SiO2)

Sandstone

Quartz Arenite (a type of sandstone composed of more than 90% quartz)

Sedimentary Rock

Wishing Stone (Quartz-veined Siltstone or Graywacke)

Hydrothermal Quartz vein in matrix of SiO2 (Quartz) and Al2O3 (Clay minerals)

Geode (unopened)

Silica-filled Concretion (SiO2)

sedimentary (man-made conglomerate)

Exposed Aggregate Concrete (Pea Gravel)

Concrete with Siliceous Alluvial Gravels

Quartz Vein in Host Rock (Pebble)

Quartz (SiO2) with sandstone or siltstone matrix

metamorphic/igneous transition

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone Pebble

Arenite (primarily SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)