Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Limestone (specifically Travertine or Tufa)
Calcium Carbonate (CaCO3)
Clear Quartz
Quartz (Silicon Dioxide - SiO2)
Quartz Crystal
Silicon Dioxide (SiO2)
Quartz Pebble (with probable inclusions or staining)
Quartz (Silicon Dioxide - SiO2)
Banded Agate (Carnelian type)
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
White Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
River Cobble (likely Basalt or Rhyolite)
Extrusive Igneous Rock (Mafic or Intermediate)
Chert (Chert Nodule with Cortex)
Microcrystalline Quartz (SiO2)
Chert (Jasper-rich)
Microcrystalline/Cryptocrystalline Quartz (SiO2)
Fancy Jasper (Mookaite style)
Silicon Dioxide (SiO2) with iron oxide impurities
Oolitic Chert
Ooidal Microcrystalline Quartz (SiO2)
Amethyst
Crystalline Silicon Dioxide with Iron impurities (SiO2)
Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide) with trace iron impurities
Jasper (likely a variety of Yellow or Mustard Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Gypsum (Wallboard/Drywall)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Jasper
Jasper (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz (Crystal Cluster)
Silicon Dioxide (SiO2)
Quartz Pebble (with potential iron inclusions)
Silicon Dioxide (SiO2)
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Sandstone (Tumbled/River Pebble)
Arenite (composed primarily of SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chrysoprase
Chalcedony (cryptocrystalline silica containing nickel); Chemical Formula: SiO2 with Ni impurities
Chert (specifically Blue or Grey Chert/Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Fossilized Brachiopod Shell in Matrix
Phylum Brachiopoda (typically Calcium Carbonate or Chitinophosphatic)
Prase Quartz on Feldspar
Quartz (Silicon Dioxide, SiO2) with Hedenbergite inclusions on Potassium Feldspar (KAlSi3O8)
Pyrite
Iron Sulfide (FeS2)
Gold Nugget
Native Gold (Au)
Sandstone (likely Fossiliferous)
Arenite / Sedimentum arenaceum
Gold Ore
Native Gold (Au)
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Lace Agate
Silicon Dioxide (SiO₂)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Amber
Succinite (fossilized tree resin)
White Zircon
Zircon (Zirconium silicate, ZrSiO4)
Carnelian Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony