Marble
Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)
Category
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
Marble
Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
Red Jasper
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Chert (often called Jasper or Flint in this color variety)
Silicon Dioxide (SiO2)
Jasper and Quartz River Pebble
Silicon Dioxide (SiO2) with impurities
Milky Quartz
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (predominantly Quartz with Hematite cementation)
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Jasper
Jasper (Silicon Dioxide, SiO2)
Red Sandstone
Arenite (with Iron Oxide cement)
Red Quartzite (River Pebble)
Quartzite (primarily Silicon Dioxide - SiO2)
Sparkling Druzy Quartz on Matrix
Silicon Dioxide (SiO2) with iron oxide inclusions
Veined Quartz
SiO2 (Silicon Dioxide)
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
Granitic Gneiss
Gneiss (High-grade regional metamorphic rock)
Agate (Geode nodule fragment)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Quartz (Double-Terminated)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Red Sandstone
Clastic sedimentary rock (primarily Quartz and Feldspar with Iron Oxide cement)
Quartz Vein in Host Rock
Hydrothermal Quartz (SiO2) in Slates/Schists
Banded Agate (specifically Carnelian Agate slice)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Wonderstone (Liesegang Sandstone)
Silicified Sandstone with Liesegang Rings (SiO2 + FeO(OH))
Green Jasper (Heliotrope / Bloodstone variety)
Silicon Dioxide (SiO₂)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Carnelian
Carnelian (Microcrystalline Quartz, SiO2 with Fe2O3 impurities)
Quartzite (specifically a river-worn cobble)
Quartzite (primarily Silicon Dioxide, SiO2)
Breciated Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Banded Agate (Pink Chalcedony)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Red Jasper
Silicon Dioxide (SiO₂)
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
Gneiss (with Quartz and Mica)
Gneiss
Red Sandstone
Arenite (Fe2O3 rich)
Ferruginous Sandstone (Gritstone)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3 and FeO(OH))
Crazy Lace Agate
Agate (Cryptocrystalline Quartz), Silicon Dioxide (SiO2)
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Red Jasper (Heliotrope family variant)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)
River Pebbles and Quartz
Mixed Igneous, Sedimentary, and Metamorphic Rocks (Silicon Dioxide SiO2 dominant)
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
Shale
Shale (Lutite)