Quartz / Limestone Gravel
SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)
Category
Browse igneous, sedimentary, and metamorphic mix specimens identified by the Rock Identifier community.
Quartz / Limestone Gravel
SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)
Jasper
Silicon dioxide (SiO2)
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite inclusions
Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Hematite
Iron(III) oxide (Fe2O3)
Pyrite (Fool's Gold) in Matrix
Iron Sulfide (FeS2)
Hematite
Iron(III) oxide (Fe2O3)
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
White Agate / Chalcedony
Silicon Dioxide (SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Yellow Quartz (Citrine or Yellow Jasper)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Botryoidal Agate / Chalcedony Geode
Silicon Dioxide (SiO2)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Aventurine (likely Green Aventurine)
Aventurine (a variety of quartz, SiO₂, with common inclusions of fuchsite)
Milky or Greenish Quartz Pebble
Silicon Dioxide (SiO2)
Banded Onyx (Green Onyx)
Banded Calcite or Travertine (CaCO3)
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
Ruby
Corundum (Al2O3 with chromium impurities)
Biotite Schist
Biotite Schist
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Chlorite or Actinolite
Cryptocrystalline Quartz (Agate/Chert)
Silicon dioxide (SiO2)
Quartz
Silicon Dioxide (SiO₂)
Quartzite
Quartzite (primarily composed of SiO O₂)
Orange Calcite
Calcium Carbonate (CaCO3)
Crackle Agate / Dyed Quartz
SiO2 (Silicon Dioxide)
Quartz Drusy on Matrix
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Banded Calcite (often sold as Mexican Onyx)
Calcium Carbonate (CaCO3)
Quartz (Small Grains)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
White Agate (Chalcedony)
Chalcedony (SiO2)
Carnelian
Carnelian (Silicon Dioxide, SiO2)
Quartz Geode
Silicon dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)