Mineral (Man Made Glass, Not Natural)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Diamond

Diamond (C)

Amethyst (or Rose Quartz)

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (Quartzite-rich Pebble)

Arenite (primarily SiO2)

Green aventurine quartz (probable)

Quartz, silicon dioxide (SiO₂), with disseminated green mica/fuchsite inclusions

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Grey Quartz (likely Smoky Quartz or Milky Quartz)

Silicon Dioxide (SiO2)

Sandstone (Weathered)

Arenite (typically SiO2 as quartz grains)

Amethyst

Amethyst (variety of Quartz, SiO2)

Chert

Microcrystalline quartz (SiO2)

Smoky Quartz

Smoky Quartz (Silicon Dioxide - SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Tumbled smoky quartz

Quartz, silicon dioxide (SiO₂), smoky variety

Fluorite (specifically Blue John or Banded Fluorite)

Calcium Fluoride (CaF2)

White quartz-rich pebble

Quartz (SiO₂), possibly milky quartz or quartzite

Green Quartz (Prasiolite/Adventurine)

Silicon Dioxide with inclusions (SiO2)

Smoky Quartz (Chlorite Inclusions)

Silicon Dioxide (SiO2) with trace Aluminum and Natural Irradiation

Quartzite (or Engineered Quartz Stone)

SiO2 (Silicon Dioxide)

Granite

Granite (a plutonic rock)

Quartz with Iron Oxide Stain

Silicon Dioxide (SiO2) with Hematite/Limonite coatings

Clear Quartz

Silicon Dioxide (SiO2)

Dyed Agate (Tumbled)

Silicon Dioxide (Chalcedony variety, artificially dyed)

Weathered limestone pebble

Limestone, primarily calcite (CaCO₃)

Chert (Flint / Jasper variant)

Microcrystalline Quartz (SiO2)

Milky quartz pebble

Quartz (SiO₂), commonly called milky quartz

Faceted Clear Quartz or Diamond Simulant

Silicon Dioxide (SiO2) if Quartz or Cubic Zirconia (ZrO2) if Synthetic

Amethyst

SiO2 (Silicon Dioxide)

Yellow Quartz (possibly dyed)

Silicon Dioxide (SiO2)

Milky quartz (likely vein quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled jasper or brecciated jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and dark mineral inclusions

Sandstone

Arenite (SiO2 predominantly)

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Quartz (Smoky Quartz / Calcite)

SiO2 (Silicon Dioxide)

Smoky Quartz

Smoky Quartz (SiO2 - Silicon Dioxide with trace impurities of aluminum)

Clear Quartz (Rock Crystal Fragments)

Silicon Dioxide (SiO2)

Weathered pegmatite or feldspar-rich granite fragment

Granitic pegmatite, composed mainly of potassium feldspar and quartz, with minor mica; exact identification is uncertain from the photograph

Shale

Argillaceous Rock

Carved quartz (likely rose quartz and green aventurine/quartz)

Quartz, silicon dioxide (SiO₂); green material may be aventurine quartz or serpentine