Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Category
Browse mineral variant specimens identified by the Rock Identifier community.
Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (varietal: Flint/River Pebble)
Cryptocrystalline Quartz (SiO2)
Banded Iron Formation (BIF)
Banded Iron Formation (predominantly Hematite Fe2O3 and magnetite Fe3O4 alternating with Chert SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Green Aventurine (Carved)
Silicon Dioxide (Quartz variant) with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O(OH)2)
Basalt Cobble
Vesicular Basalt (Mafic Extrusive)
Chert (specifically Flint or Common Opal variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green Quartz (including Prase or Aventurine variants)
Silicon Dioxide (SiO2) with inclusions (likely Actinolite or Chlorite)
Banded Agate (Silk Agate or Maligano Jasper variant)
Silicon Dioxide (SiO2)
Quartzite
Metamorphic rock predominantly composed of Quartz (SiO2)
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
Yellow Chalcedony (common opal or chert variant)
Silicon Dioxide (SiO2)
Conglomerate
Clastic sedimentary rock (Psephite)
Rounded pebble, likely granite or granitic gneiss
Granite: quartz + feldspar + mica; the specimen may be a granitic metamorphic variant
Chert (Jasper/Carnelian variety)
Microcrystalline Quartz (SiO2)
Chert (Common Opal/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Botryoidal Chalcedony (Desert Rose / Grape Agate variant)
Silicon Dioxide (SiO2)
Quartz (Clear Quartz and Rose Quartz variants)
Silicon Dioxide (SiO2)
Fossilized Coral (Petoskey Stone or similar Hexagonaria variant)
Hexagonaria percarinata (Fossilized Coral)
Obsidian (Black Obsidian)
Amorphous volcanic glass (primarily SiO2)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Peridotite (Dunite/Lherzolite)
Ultramafic Peridotite
Chert (Lake Superior Agate variant)
Microcrystalline Quartz (SiO2)
Chert (Hagstone/Gasket Rock variant)
Chert (SiO2)
Wood Stone (Dragon Stone variant)
Argillaceous Sedimentary Rock
Red Jasper (Heliotrope family variant)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Quartzite (Milky or Cloudy Quartz variant)
Silicon Dioxide (SiO2)
Chert (specifically Jasper or Flint variant)
Microcrystalline Quartz (SiO2)
River Pebble (Gneiss or Quartzite variant)
Course-grained Metamorphic Rock (likely SiO2 dominant)
Chert (specifically Flint or Jasper variant)
Microcrystalline silica (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)
Greenstone (Greywacke or Nephrite Jade variant)
Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)
Chert (specifically Flint or Jasper variant)
Cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Fancy Jasper (Ocean Jasper or River Jasper variant)
Silicon Dioxide with inclusions (SiO2)
Chert (and its variety Flint)
Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz
Pumice
Highly vesicular volcanic glass (unnamed scientific variant: Rhyolitic/Andesitic Pumice)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (Yellow or Ochre Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Light Grey / Flint variant)
Cryptocrystalline Quartz (SiO2)