Quartz on Matrix
Silicon Dioxide (SiO2)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Quartz on Matrix
Silicon Dioxide (SiO2)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Banded Gneiss
Gneiss (high-grade metamorphic silicate rock)
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Pumice
Pumice (volcanic rock)
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
Sandstone with Quarzite clasts
Arenite (SiO2 based)
Banded Sandstone
Arenite (with iron oxide banding)
Quartz (Milky/Crystalline)
Silicon Dioxide (SiO2)
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)
Desert Varnish on Sandstone
Ferromanganese coating on Quartz Arenite
Chert (Flint)
Microcrystalline Quartz (SiO2)
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Basalt with Quartz/Calcite Vein
Amygdaloidal Basalt (matrix) with Mineral Vein filling
Petrified Wood
Silicified Wood (SiO2)
Pink Opal
Hydrated silicon dioxide (SiO2·nH2O) with inclusions
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
Pyrite
Pyrite (Iron sulfide, FeS₂)
N/A (Non-Geological Specimen)
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Gneiss (Pebble)
Gneiss
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2 permineralization)
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
Orange Calcite
Calcium Carbonate (CaCO3)
Green Calcite
Calcium Carbonate (CaCO3)
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Quartz (on matrix)
Quartz (Silicon Dioxide, SiO₂)
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Geode (Unopened)
Siliceous Geode (SiO2)
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))