Geode (Unopened)
Siliceous Geode (SiO2)
Category
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Geode (Unopened)
Siliceous Geode (SiO2)
Coal (Bituminous)
Sedimentary carbonaceous rock
Blue Chalcedony
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine-colored Quartz Pebble)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Quartzite
Quartzite (primarily SiO2)
Quartz Grain
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
Kunzite (Pink Spodumene)
Spodumene, LiAl(SiO3)2
Pink Dyed Agate
Silicon Dioxide (SiO2) - Variety Agate
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Gneiss
Metamorphic rock of high-grade regional metamorphism
Granite (with Almandine Garnet inclusions)
Granite composed primarily of Quartz (SiO2), K-Feldspar (KAlSi3O8), and Almandine Garnet (Fe3Al2(SiO4)3)
Crazy Lace Agate
Silicon Dioxide (SiO2) with impurities
Jasper with Quartz vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Petrified Wood
Silicified Wood (primarily SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Zebra Marble
Recrystallized Calcite (CaCO3) with Carbonaceous Impurities
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
Quartz Pebble
Silicon Dioxide (SiO2)
Dyed Magnesite (often sold as Red Turquoise or Howlite)
Magnesium Carbonate (MgCO3)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Fluorite (Rainbow Fluorite Tower)
Fluorite (Calcium Fluoride, CaF2)
Fluorite
Calcium Fluoride (CaF2)
Quartz (Milky/Crystalline fragment)
Silicon Dioxide (SiO2)
Caribbean Calcite
Calcite (CaCO3) with Aragonite (CaCO3)
Limestone
Carbonate rock (CaCO3)
Agate (specifically Botswana or Banded Agate variety)
Chalcedony (Silicon Dioxide, SiO2)
Sandstone Beach Pebble
Clastic Sandstone (SiO2 - Quartz-dominant)
Blue Chalcedony (Tumbled)
Silicon Dioxide (SiO2)
Quartzite with inclusions
Metamorphosed Quartz-rich Rock (SiO2)
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Chert (specifically var. Flint or Jasper-rich Breccia)
Microcrystalline Quartz (SiO2)
Chert (Pebble)
Chert (Microcrystalline Quartz, SiO2)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Chert (Jasper-bearing)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Chert (Iron-stained or Jasperoid)
Microcrystalline Quartz (SiO2)
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Fluorite
Calcium Fluoride (CaF2)