Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
Category
Browse not a rock (synthetic material) specimens identified by the Rock Identifier community.
Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide - SiO2)
Bumblebee Jasper
Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
Pink Quartzite
Quartzite (primarily SiO2)
Anthracite Coal
Low-grade metamorphic carbonaceous rock
Granite
Phaneritic intrusive felsic igneous rock
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Quartzite
Quartzite (SiO2 silicon dioxide)
Carnelian
Carnelian (a variety of Chalcedony, SiO2) colored by iron oxide
Rock Salt / Halite Crust
Halite (Sodium Chloride, NaCl)
Carnelian
Carnelian (Silicon Dioxide - SiO2)
Bloodstone Jasper (Heliotrope)
SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz
Cloudy Quartz
Quartz (Silicon Dioxide, SiO2)
Rhyolite
Rhyolite
Jasper (specifically Brecciated or Agated Jasper)
Silicon Dioxide (SiO2) - Chalcedony with impurities
Green Jasper (Heliotrope / Bloodstone variety)
Silicon Dioxide (SiO₂)
Quartzite (Yellow/Tan river stone variety)
Quartzite (primarily SiO2)
Quartz River Cobble (Yellow Jasper/Quartzite variant)
Quartzite (primarily Silicon Dioxide, SiO2)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
Gneiss
Gneiss
Carnelian (Agate/Chalcedony)
Silicon Dioxide (SiO2)
Agate (specifically a small Chalcedony nodule)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Flint (Chert)
Cryptocrystalline Quartz (SiO2)
Quartz / Limestone Gravel
SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)
Oolitic Ironstone
Sedimentary Ooidal Ironstone (Limonite/Hematite mixture)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
River Stone / Siltstone
Siltstone (composed of lithified silt)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Orbicular Granite (specifically Mustard or Yellow Tonalite/Granodiorite)
Orbicular Quartz Diorite / Tonalite
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Banded Agate (specifically Botryoidal/Orbicular Agate)
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) - variety Carnelian (Chalcedony)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide