Milky Quartz (Water-worn pebble)
Quartz (Silicon Dioxide, SiO2)
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Milky Quartz (Water-worn pebble)
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Howlite
Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (and its variety Flint)
Silicon dioxide (SiO2) / Microcrystalline quartz
Jasper with Quartz Veining
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 dominated)
Pink Granite (Potassium-rich)
Phaneritic Felsic Igneous Rock (K-Feldspar Granite)
Pyrite
Iron Sulfide (FeS2)
Chert (Common Opal variant)
Microcrystalline Quartz (SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
River Cobble (Conglomerate context)
Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)
Quartz Pebble (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
Black Opal
Hydrated Silica (SiO2·nH2O)
Dendritic Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Sandstone
Arenite (composed primarily of SiO2, or Silicon Dioxide)
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)
Banded Agate
Agate (Cryptocrystalline variety of Silica, SiO2)
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
Quartzite Pebble
Quartzite (composed primarily of Silica, SiO2)
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
Bloodstone (Heliotrope)
Chalcedony (SiO2) with inclusions of Iron Oxide or Red Jasper
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Agate (translucent slice)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz
Silicon dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Quartz (Rose or Milky variety fragment)
Silicon Dioxide (SiO2)
Blue Lace Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Chert (specifically Yellow/Common Opal or Jasper mixture)
Silicon Dioxide (SiO2)
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz and/or feldspar)
Bryozoan Fossil
Phylum Bryozoa (commonly known as 'moss animals')
Chert
Chert (microcrystalline quartz, SiO2)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)