Mineral Like (Natural Glass)

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Pink Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Granite

Phaneritic intrusive igneous rock

Granite

Phaneritic Igneous Rock (Granite)

Green Fluorite

Calcium Fluoride (CaF2)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

metamorphic

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Obsidian

Obsidian (Volcanic Glass)

Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

Sandstone (with potential trace fossils)

Clastic sedimentary rock (primarily SiO2)

Quartz

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Sedimentary Rock (specifically a clastic sedimentary rock formed into a cobble)

River Cobble (likely Sandstone or Siltstone type)

Sandstone or Siltstone (common rock types that form river cobbles)

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Cubic Zirconia (Diamond Simulant)

Zirconium Dioxide (ZrO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Druzy Quartz on Milky Quartz

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Lodolite (Garden Quartz)

Silicon Dioxide (SiO2) with inclusions (Chlorite, Hematite, etc.)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Rose Quartz

Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Quartz (Milky or Cloudy Quartz)

Quartz (Silicon Dioxide, SiO2)

Sedimentary or Metamorphic

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Sandstone

Arenite (SiO2 primarily)

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Petrified Wood (Silicified Wood)

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

Red Tigers Eye (Bull's Eye)

SiO2

Mineral

Bismuth Crystal

Bismuth (Bi)

Sandstone

Arenite (SiO2 principal)

Sandstone (likely Quartzose)

Arenite (SiO2 principal mineral)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

Sedimentary (if natural Jasper) or Artificial (if Slag)

Jasper (Multi-colored) / Sea Glass Slag

Silicon Dioxide (SiO2) with impurities of Iron Oxide

Sheen Obsidian

Volcanic glass (SiO2 with inclusions)

Obsidian

Volcanic Glass (SiO2)

Sandstone (Stream-rounded Cobble)

Arenite (composed primarily of SiO2, Silica)

Quartz Sand Gravel

Silicon Dioxide (SiO2)