Quartzite
Quartzite (primarily 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.
Quartzite
Quartzite (primarily SiO2)
Chert (Jasper variety)
Microcrystalline quartz (SiO2)
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Lapis Lazuli
Complex metamorphic rock containing Lazurite ((Na,Ca)8(AlSiO4)6(SO4,S,Cl)2), Calcite, and Pyrite
Quartz on Host Rock
Silicon Dioxide (SiO2)
Emerald (Tumbled Beryl)
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Chert (Agatized Chert)
Microcrystalline Quartz (SiO2)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
River Quartzite Siltstone
Quartz-rich Meta-siltstone (SiO2 dominated)
Chert (Nodule/Pebble)
Chert (Silicon Dioxide, SiO2)
Chalcedony (Botryoidal Agate vein)
Chalcedony (Microcrystalline Quartz) - SiO2
Coarse Sand Grain / Lithic Fragment
Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)
Lapis Lazuli
Complex metamorphic rock primarily composed of Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite
Chert (White Chert)
Microcrystalline Quartz (SiO2)
Banded Calcite (Tumbled)
Calcium Carbonate (CaCO3)
Not a rock, mineral, or geological specimen
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Yellow Chert (Jasper)
Chalcedony (SiO2) with iron oxide inclusions
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Red Quartzite / Ferruginous Sandstone
Quartzite (SiO2 with iron oxide impurities)
Chert (Nodule)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe) impurities
Chert Pebble
Microcrystalline Quartz (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) - Variety: Chalcedony
Orange Calcite
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Chert (containing Flint and Chalcedony)
Microcrystalline Quartz (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartzite
Quartzite
Sandstone (Pebble)
Arenite (composed primarily of SiO2)
Chalcedony in Host Rock
Chalcedony (SiO2)
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Amethyst Quartz
Silicon Dioxide (SiO2)
Red Jasper with Quartz Veining
Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Tan/Grey variety)
Silicon Dioxide (SiO2)