Gneiss
Gneiss (High-grade Metamorphic Rock)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade Metamorphic Rock)
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Red Sandstone (Arkose)
Clastic Sedimentary Rock (Lithic Arkose)
Smoky Quartz
SiO2 (Silicon Dioxide)
Sandstone (Grooved/Weathered)
Arenite (composed primarily of Quartz and Lithic fragments)
Chert (Yellow or Ochre Jasper variant)
Microcrystalline Quartz (SiO2)
Gneiss
Gneiss
Quartz Geode
Silicon Dioxide (SiO2)
Gneiss (Pebble)
Gneiss
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Novaculite Variety)
Microcrystalline Quartz (SiO2)
Green Jasper
Silicon Dioxide (SiO2)
Gneiss (with Mica and Quartz)
Gneissic Metamorphic Rock
Quartz Geode
Crystalline Silicon Dioxide (SiO2) within a nodule
Gneiss
Gneiss (High-grade Metamorphic Rock)
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Pyrite in Matrix (Fool's Gold)
Iron Disulfide (FeS2)
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
Chert / Jasper
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Heart-shaped Pebble)
Cryptocrystalline quartz (SiO2)
Unidentifiable Specimen
Undetermined
Sandstone Concretion
Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Magnetite (Lodestone)
Magnetite (Fe3O4)
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with impurities
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Ammonite Fossil
Ammonoidea (primarily composed of Calcite, CaCO3)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Fluorite
Calcium Fluoride (CaF2)
Chert (Nodular Chert)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (often called Flint or Jasper based on color)
Microcrystalline Silica (SiO2)
Chert (Gravel / Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petoskey Stone
Hexagonaria percarinata
Chert (Field Stone/Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically a stream-worn Chert Nodule)
Sedimentary Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)