Hag Stone
Porous sedimentary rock (typically Flint, Chert, or Sandstone) with naturally occurring holes
sedimentary
Category
Organic (Zoogenic)
Browse organic (zoogenic) specimens identified by the Rock Identifier community.
Diorite (River Cobble)
Intermediate Phaneritic Plutonic Rock
Igneous
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
mineral
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chalk (Sedimentary Limestone)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
sedimentary
Sand Dollar Fossil (Echinoidea)
Class Echinoidea (likely order Clypeasteroida), CaCO3 (Calcite)
sedimentary
Greenschist
Greenschist (chlorite-epidote schist)
metamorphic
Gold-bearing Quartz
Auriferous Quartz (SiO2 with native Au)
mineral
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Calcite in Matrix
Calcium Carbonate (CaCO3)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Arrowhead Fragment)
Chert / Microcrystalline Silicon Dioxide (SiO2)
sedimentary
Quartzite with Gneissic Banding
Quartzite (primarily SiO2) with mafic mineral inclusions
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)
igneous
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Red Jasper (Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (with small quartz inclusion)
Microcrystalline Silica (SiO2)
sedimentary
Greenschist (Chlorite Schist)
Greenschist (containing chlorite, actinolite, and epidote)
metamorphic
Chert (Flinty variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Gold Ore in Quartz/Schist
Auriferous Quartz and Sulfide-bearing Schist
Metamorphic/Igneous (Hydrothermal)
Granite
Phaneritic plutonic rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
igneous
Quartzite pebble
Quartzite (primarily SiO2)
metamorphic
Schist (Graphite or Mica rich)
Crystalline Schist (often containing Muscovite, Biotite, or Graphite)
metamorphic
Jasper
Silicon dioxide (SiO2)
sedimentary
Gold Ore in Quartz
Auriferous Quartz (Au + SiO2)
igneous
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral with metamorphic or sedimentary host
Quartzite
Quartzite (primarily SiO2)
metamorphic
Blue Calcite
Calcium Carbonate (CaCO3)
Mineral
Banded Chert
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Chert (with Iron Staining)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite Pebble
Felsic intrusive igneous rock (consisting primarily of Quartz and Feldspar)
igneous
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Flint / Chert
Silicon Dioxide (SiO2)
sedimentary
Chert (Common Opal/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous