Sedimentary (Silica Rich Mineral Variety)

Chert (variations include Chalcedony and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fuchsite on Quartzite

Muscovite (Chromium-bearing) K(Al,Cr)2(AlSi3O10)(OH)2

Red Jasper

Jasper (SiO2 with Fe2O3 inclusions)

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock with secondary mineral infilling)

Sandstone (Wonderstone)

Silicified Sandstone / Orthoquartzite with Liesegang rings

Chert (specifically Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Rhyolite

Rhyolite (High-silica volcanic rock)

Smoky Quartz

Silicon Dioxide (SiO2)

Blue-dyed Quartz Druzy

Silicon Dioxide (SiO2) with artificial pigment

Amethyst

Amethyst (SiO2 - Silicon Dioxide with iron impurities)

Indian Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Red Jasper (Brecciated Jasper)

SiO2 (Silicon Dioxide) with Ferric Iron inclusions

Red Sandstone (Iron-Rich)

Arenite (Fe2O3)

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Sandstone (Calcareous or Ferruginous)

Clastic sedimentary rock (SiO2 with CaCO3 or Fe2O3 cement)

Rhyolite

Rhyolite

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Rose Quartz

SiO2 (Silicon Dioxide)

Gneiss (specifically a Granitic Gneiss)

Gneiss (Composition: Quartz, Feldspar, Mica)

Limonite (Yellow Ochre)

FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)

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

Quartz (SiO₂ - Silicon Dioxide)

Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)

Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.

Petrified Wood

Silicified Wood (SiO2 permineralization)

Sandstone (likely Arkosic or Lithic Sandstone)

Clastic Sedimentary Rock (SiO2 with assorted minerals)

Druzy Quartz on Matrix (likely Limestone or Sandstone)

Silicon Dioxide (SiO2) with various trace impurities

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Rainbow Moonstone with Black Tourmaline

White Labradorite (Feldspar variety, (Na,Ca)(Al,Si)4O8) with Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Mookaite Jasper

Silicon Dioxide (SiO2) with impurities

Ruby Fuchsite / Ruby in Fuchsite

Ruby (Al2O3 variety corundum) and Fuchsite (K(Al,Cr)2AlSi3O10(OH)2 - a chromium-rich variety of muscovite mica) in Quartz matrix

Eagle Eye Stone (Green Tiger's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Orange Quartz with Hematite inclusions

Quartz (SiO2) with Hematite (Fe2O3) inclusions

Chert (Flint)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (and/or Chalcedony)

Microcrystalline Silica (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Milky Quartz with Epidote or Chlorite inclusions

Silicon Dioxide (SiO2) with inclusions of Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)