Quartz Geode Fragment
Silicon Dioxide (SiO2)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Rough Quartz (or Quartzite pebble)
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (quartz-feldspar-biotite metamorphic rock)
Quartzite Beach Pebble
Quartzite (primarily SiO2)
Nuummite
Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Chert (often called Jasper in this color)
Microcrystalline quartz (SiO2)
Chert (White/Gray variety)
Chert (SiO2)
Ferruginous Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Coquina
Coquina (Bioclastic Limestone)
Crinoid Fossil Stem Segment
Class Crinoidea (Echinodermata)
Fossilized Coral (Petoskey-like or Favosites)
Anthozoa (Fossilized Coral)
Banded Chert
Microcrystalline silicon dioxide (SiO2)
Ferruginous Sandstone (Ironstone)
Ferruginous Sandstone / Limonite-cemented Quartz Sandstone
Red Sandstone
Arenite (primarily SiO2 with hematite/iron oxide coating)
Chert (varietal Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Septarian Nodule
Septarian Nodule (Mixture of Calcite, Aragonite, and Limestone/Clay)
Chalcedony in Matrix
Silicon Dioxide (SiO2)
Chert (often called Jasper or River Rock)
Chert (SiO2)
Banded Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Jasper (Iron-rich Microcrystalline Quartz)
Silicon Dioxide (SiO2) with Hematite inclusions
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Garnet-Bearing Gneiss
Almandine-Garnet Gneiss
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
Geode (Unopened)
Silica-lined Vug (primarily SiO2)
Ferruginous Quartz (Carnelian-tinted Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Quartz (Milky/Vein Quartz)
Silicon Dioxide (SiO2)
Yellow Jasper
Chalcedony (Silicon Dioxide, SiO2)
Honey Calcite (Yellow Calcite)
Calcium Carbonate (CaCO3)
Quartz (Milky or Clear Quartz fragment)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Quartzite
Quartzite (primarily SiO2)
Jasper (Zebra Jasper)
Silicon Dioxide (SiO2) with impurities
Red Sandstone Pebble
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 staining)
Sandstone
Arenite (primarily SiO2, silica)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)