Obsidian with Spherulitic Devitrification (Snowflake Obsidian/Mahogany related)
Volcanic Glass (70% or more SiO2)
Category
Browse not a geological specimen specimens identified by the Rock Identifier community.
Obsidian with Spherulitic Devitrification (Snowflake Obsidian/Mahogany related)
Volcanic Glass (70% or more SiO2)
Jasper (Iron-rich Microcrystalline Quartz)
Silicon Dioxide (SiO2) with Hematite inclusions
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Concrete Fragment
Hardened Portland Cement Composite
Milky Quartz (with Iron staining)
Silicon Dioxide (SiO2)
Banded Rhyolite (likely Green Jasper/Agate variety)
Silicon Dioxide (SiO2) with mineral inclusions
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
Granite (with mafic xenolith)
Phaneritic Felsic Plutonic Rock
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz, SiO2)
Druzy Quartz (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Fossiliferous Limestone with Crinoid stems
Calcite-rich Biogenic Sedimentary Rock (CaCO3)
Quartz on Chlorite Schist
Chlorite Schist (Mg,Fe)3(Si,Al)4O10(OH)2 with Quartz (SiO2)
Agate (Thunderegg segment)
Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony
Quartzite
Quartzite (primarily SiO2)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Zebra Jasper (Zebra Stone)
Tumbled Silicon Dioxide (SiO2) with impurities
Sandstone (Greywacke/Lithic Sandstone)
Arenite (composed primarily of SiO2)
Tourmalinated Quartz
Silicon Dioxide (SiO2) with inclusions of Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)
Aquamarine (Beryl)
Beryllium aluminum silicate (Be3Al2Si6O18)
Quartz with mica and feldspar (Pegmatite fragment)
Granitic Pegmatite (composed mainly of SiO2 with KAlSi3O8)
Banded Calcite (often sold as Caribbean Calcite or Honey Calcite)
Calcium Carbonate (CaCO3)
Jasper
Silicon dioxide (SiO2) with iron oxide impurities
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 based)
Hematite
Iron(III) oxide (Fe2O3)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz River Pebble
Quartz (Silicon Dioxide, SiO2)
Agate (specifically Chalcedony nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Fossilized Coral (Petoskey Stone or similar)
Hexagonaria percarinata (Order: Rugosa)
Yooperlite (Syenite clasts with Sodalite)
Fluorescent Sodalite-bearing Syenite
Sodalite
Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2)
Orange Calcite
Calcium Carbonate (CaCO3)
Rose Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)