Grey Chalcedony (Tumbled)
Chalcedony (SiO2)
mineral
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
sedimentary
Sandstone
Arenite (primarily composed of SiO2)
sedimentary
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Shale
Shale (comprised mostly of clay minerals and quartz)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
sedimentary
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
mineral
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sunstone
Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Sunstone
Oligoclase (Plagioclase Feldspar Group) - (Ca, Na)(Al, Si)4O8
mineral
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Quartz
mineral
Sandstone
Arenite (primarily SiO2 with various cementing agents)
sedimentary
Chert (Flint nodule)
Silicon dioxide (SiO2)
sedimentary
Chert (and Limestone)
Chert (consisting of Microcrystalline Quartz, SiO2)
sedimentary
Nephrite Jade
Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2
Mineral
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Mother of Pearl (Nacre)
Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Chert (with Lichen)
Microcrystalline Quartz (SiO2)
sedimentary
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
sedimentary or metamorphic
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
sedimentary
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Vein Outcrop
Silicon Dioxide (SiO2)
mineral
Quartz Crystal Cluster
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
igneous
Jasper (Banded Argillite/Chert mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Sandstone (Quartzite-rich)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
sedimentary
Sandstone
Arenite (Clastic Sedimentary Rock)
sedimentary
Sandstone (with potential iron-oxide weathering)
Arenite (SiO2 based)
sedimentary
Not a geological specimen
N/A (man-made object)
N/A