Unidentifiable Specimen
Undetermined
Category
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
Unidentifiable Specimen
Undetermined
Chert (and Flint)
Silicon Dioxide (SiO2)
Chert (specifically White Chert or Novaculite)
Silicon Dioxide (SiO₂)
Yellow Quartz (Citrine or Quartzite Pebble)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Shale
Fissile mudstone (rich in clay minerals and quartz)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone Cobble
Clastic Sedimentary (Sandstone)
White Marble
Recrystallized Calcite (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Yellow Quartz
Silicon Dioxide (SiO2)
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
N/A (The provided image is a storyboard/digital document)
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartzite
Quartzite (primarily SiO2)
Chalcedony (Botryoidal or Tumbled)
Chalcedony (SiO₂)
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Dyed Agate
Silicon Dioxide (SiO2) - Variety Agate / Chalcedony
Coquina
Coquina (Biogenic Limestone / CaCO3)
Basalt
Basalt (Mafic volcanic rock)
Granite Pebble (Pink Granite)
Phaneritic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Greisen (Quartz-Muscovite-Turretine Rock)
Greisen
Citrine
Silicon Dioxide (SiO₂)
Blue Chalcedony
Silicon Dioxide (SiO2)
Quartzite Pebble
Quartzite (primarily SiO2)
Fluorite (Blue)
Calcium Fluoride (CaF2)
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Calcite
Calcite (CaCO3)
Sandstone
Arenite (SiO2 principal)
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Sandstone (likely Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Sunstone
Oligoclase (Plagioclase Feldspar Group) - (Ca, Na)(Al, Si)4O8
Yellow Quartz (Citrine-colored Quartz)
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2) with iron impurities
Rose Quartz
Silicon Dioxide (SiO2)
Limonite (Iron Stone/Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Citrine Quartz Crystal Cluster
Silicon Dioxide (SiO2) with iron impurities
Ferruginous Sandstone with Quartz Inclusions
Clastic Sedimentary Rock (Iron-rich Sandstone)