Sedimentary (Chemical)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Limonite with Quartz (Gossan)

Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)

Basalt with Iron Oxidation

Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)

Amazonite (Green Feldspar)

Microcline (variety Amazonite), Chemical Formula: K(AlSi3O8)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Gold in Quartz Matrix

Native Gold (Au) with Quartz (SiO2) and Slate/Shale

Diabase (also known as Dolerite)

Diabase

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Quartzite (River Pebble)

Meta-quartzite (composed primarily of SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Yellow Quartzite (River Cobble)

Quartzite (SiO2)

Quartzite

Quartzite (mainly SiO2)

Quartz (Milky or Citrine-leaning)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite (River Cobble)

Metamorphosed Quartz Sandstone (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Quartz pebble

Silicon Dioxide (SiO2)

Gold Flake

Native Gold (Au)

Caliche (also known as hardpan, calcrete, kankar)

Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.

Obsidian (specifically Mahogany Obsidian)

Volcanic glass (high silica content, SiO2)

Unakite

Unakitized granodiorite / Quartz-Epidote-Feldspar rock

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Green Aura Quartz

Silicon Dioxide (SiO2) bonded with metallic vapors (typically Gold, Chromium, or Titanium)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Cavansite

Cavansite (Ca(VO)Si4O10·4H2O)

Quartz (River Pebble)

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartzite (Iron-stained)

Quartzite (SiO2 with iron oxides)

Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Moss Agate / Carnelian Agate

Silicon Dioxide (SiO2) with iron and manganese inclusions

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (Primary mineral: SiO2)

Dyed Agate Geode (Pink/Magenta)

Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Yellow Quartzite Pebble

Quartzite (primarily SiO2)

Howlite (Dyed to resemble Turquoise)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)