Brecciated Chert
Sedimentary Chert (SiO2) with Calc-Silicate mineralization
Category
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Brecciated Chert
Sedimentary Chert (SiO2) with Calc-Silicate mineralization
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
Limestone
Calcium Carbonate (CaCO3)
Agate (Lace Agate Geode Slice)
Silicon Dioxide (SiO2)
Fossil Shell in Sedimentary Matrix
Bivalvia (fossil) in Calcium Carbonate Matrix
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Chert / Flint
Cryptocrystalline quartz (SiO2)
Quartzite
Quartzite (SiO2)
Quartz Druzy on Basalt
Silicon Dioxide (SiO2) on Mafic Volcanic Rock
Liesegang Banded Sandstone (Wonderstone)
Ferruginous Sandstone with Liesegang Rings
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Chert (Common Opal variant)
Microcrystalline Quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
River Pebble (Greywacke or Siltstone)
Clastic Sedimentary Rock
Blue Calcite
Calcium Carbonate (CaCO3)
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
Goethite (likely as part of Limonite/Ironstone)
Goethite (α-FeOOH)
Quartzite
Quartzite (SiO2)
Banded Chert (River Cobble)
Microcrystalline Quartz (SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Celestine (or Celestite)
Celestine (Strontium Sulfate, SrSO4)
Chert (often called Jasper or River Siltstone)
Chert (SiO2)
Chalcedony (River Stone)
Microcrystalline Quartz (SiO2)
Granite (River Cobble)
Phaneritic Plutonic Felsic Rock (Granite)
Quartzite
Quartzite (SiO2)
Labradorite
Labradorite (Ca, Na)(Al, Si)4O8
Limestone
Calcium Carbonate (CaCO3)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (specifically Yellow Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Granite (Pink/Red Orthoclase variety)
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
Fossiliferous Limestone (with Coralline Inclusions)
Calcium Carbonate (CaCO3)
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartzite
Quartzite (mostly SiO2)
Veined Quartz
SiO2 (Silicon Dioxide)
Vesicular Basalt (or Porphyritic Scoria)
Vesicular Basalt
Amethyst (Rose-tinted/Pale variety)
Silicon Dioxide (SiO2) with iron impurities
Quartzite
Quartzite (SiO2)
Obsidian
Extrusive igneous volcanic glass (rich in SiO2)
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Jasper Agate (specifically Brecciated Jasper)
Silicon Dioxide (SiO2) with iron oxide and clay impurities