Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Category
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Quartz
Silicon dioxide (SiO₂)
Obsidian
Obsidian (Volcanic Glass, SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Chert (Quartz-rich)
Microcrystalline Silica (SiO2)
Agate (specifically Waterline or Onyx-type Agate)
Silicon Dioxide (SiO2) - variety Chalcedony
Brecciated Chert with Quartz Veining
Microcrystalline Quartz (SiO2) Breccia
Shungite
Carbon-rich mineraloid (Amorphous carbon)
Fossilized Coral (Petrified Coral)
Anthozoa (Scleractinia)
Chert (Jasper/Flint variant)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Flint / Chert
Silicon dioxide (SiO2)
Chert (varieties: Flint or Chalcedony)
Microcrystalline Quartz (SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Ferruginous Sandstone (Gozzan)
Iron-rich clastic sedimentary rock with Limonite/Goethite
Opal (Precious Opal)
Hydrated Silica (SiO2·nH2O)
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Copper-bearing Quartz Vein in Host Rock
Quartz with Malachite/Chrysocolla staining
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock pebble
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Ferruginous Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions (Limonite/Hematite)
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Flint / Chert Nodule
Sedimentary cryptocrystalline quartz (SiO2)
Quartz (Chert/Chalcedony variant)
Silicon dioxide (SiO2)
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
Quartz Geode with Calcite
Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)
Chert (Limestone-based)
Silicon dioxide (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Quartz pebble or seed/crumb
SiO2 (if quartz)
Chert (Flint)
Chert (SiO2)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Bumblebee Jasper
Calcite with Arsenic and Sulfur inclusions
Limonitic Sandstone with Inclusion
Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Tumbled granite
Granite, chiefly quartz, feldspar, and mica
Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)
Zirconia (Ceramic) & Ion-X Glass
Zirconium Dioxide (ZrO2) and Ion-strengthened Aluminosilicate Glass
Chert (Flint)
Silicon Dioxide (SiO2)