Blue Sapphire
Corundum (Al2O3)
Category
Browse sedimentary or igneous fragment specimens identified by the Rock Identifier community.
Blue Sapphire
Corundum (Al2O3)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Banded River Cobble with Mafic Dike
Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion
Calcite
Calcium Carbonate (CaCO3)
Milky Quartz Pebble with Chert
Silicon Dioxide (SiO2)
Pink Garnet (likely Almandine or Rhodolite)
Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)
Quartz (Drusy/Crystalline)
Silicon Dioxide (SiO2)
Citrine
SiO2 (Silicon Dioxide)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Blue Calcite
Calcium Carbonate (CaCO3)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
Chert
Chert (microcrystalline quartz, SiO2)
Dalmatian Jasper
Peralkaline rhyolite
Blue Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
Jasper (Cream/Yellow variety)
Jasper (Microcrystalline Quartz, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Ruby (Pink to Red Corundum)
Al2O3 (Corundum with Chromium impurities)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Blue Star Sapphire
Corundum (Al2O3)
Ruby
Corundum (Al2O3 with Chromium impurities)
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
Quartz crystal with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Copper-bearing Quartz (likely Malachite on Quartz matrix)
Cu2CO3(OH)2 (Malachite) on SiO2 (Quartz)
Magnetite / Hematite rich ore
Magnetite (Fe3O4) or Hematite (Fe2O3)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Graphite
Graphite (C)
White Chalcedony (Agate)
Silicon Dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
Agate Nodule / Weathered Chert
SiO2 (Silicon Dioxide - Microcrystalline Quartz)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (Milky Variant)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)