Blue Calcite
Calcite (Calcium Carbonate, CaCO3)
Category
Browse sedimentary (silica rich mineral variety) specimens identified by the Rock Identifier community.
Blue Calcite
Calcite (Calcium Carbonate, CaCO3)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Druzy Quartz
Quartz (Silicon Dioxide, SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
Chert
Chert (microcrystalline quartz, SiO2)
Chert (and Flint variant)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2) - Jasper (Microcrystalline Quartz)
Sandstone
Arenite (SiO2 primarily)
Chert (Arrowhead/Artifact Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Obsidian
Obsidian (principally SiO2)
Red Jasper
Silicon Dioxide with Iron inclusions (SiO2)
Chert (Tan/Yellow variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically White Chert or Novaculite)
Silicon Dioxide (SiO₂)
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Jasper with Agate and Quartz Inclusions
Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Chert (variations include Flint/Jasper)
Cryptocrystalline Quartz (SiO2)
Quartzite (River Cobble)
Quartzite (dominant mineral: Quatrz, SiO2)
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
Serpentine, likely a variety of Chrysoprase (green chalcedony) or a similar translucent green mineral.
Serpentine Group Minerals (e.g., Antigorite, Lizardite) or Chalcedony (SiO2) with nickel impurities for Chrysoprase green.
Sandstone (Quartzose)
Arenite (predominantly SiO2)
Coarse-grained Jasper or Jasper Conglomerate
Silicon Dioxide with Iron Oxide (SiO2) + Fe2O3
Amethyst
Quartz (SiO2) with trace iron impurities
Sandstone
Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)
Chert (Yellow/Tan Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (varietal: Flint or River Pebble)
Silicon Dioxide (SiO₂)
Chert (and/or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz (Milky/Gravel variety)
Silicon Dioxide (SiO2)