Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Mineral
Category
Sedimentary Rock Or Mineral (Depending On Origin And Purity)
Browse sedimentary rock or mineral (depending on origin and purity) specimens identified by the Rock Identifier community.
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
mineral
Jasper
Jasper (Silica/Quartz) - SiO2
sedimentary
Green Slag Glass
Cullet (Amorphous Silicon Dioxide with impurities)
Man-made rock-like material
Kyanite
Kyanite (Al2SiO5)
mineral
Milky Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Metamorphic Rock
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Limestone
CaCO3 (principally composed of Calcite)
sedimentary
Red Granite
Phaneritic Plutonic Rock (High Potassium Feldspar)
igneous
Fossilized Brachiopod/Bivalve in Limestone
Brachiopoda or Bivalvia fossil in Calcite/Limestone (CaCO3)
sedimentary
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
Mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Quartz (likely a clear or rock crystal variety)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
sedimentary/igneous association
Not a geological specimen
N/A (man-made object)
N/A
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Silver (Native Element)
Ag (Argentum)
mineral
Sandstone with trace fossil
Sandstone, possibly with Skolithos or similar trace fossil
sedimentary
Quartzite (or Milky Quartz pebble)
Quartzite (Metamorphosed Sandstone) / Silicon Dioxide (SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Ferruginous Quartz (Iron-stained Quartzite)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
metamorphic
Rough Quartz (likely Rose or Amethyst variety)
Silicon Dioxide (SiO2)
mineral
Milky Quartz Vein with Iron Staining
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz (specifically Citrine or Yellow Quartz)
Silicon Dioxide (SiO2)
mineral
Green Tourmaline
Verdelite (Silicate mineral); Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
mineral
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous
Carnelian
Carnelian (a variety of Chalcedony, SiO₂)
Mineral
Chert (Gravel Bit)
Microcrystalline silica (SiO2)
sedimentary
Quartz in Host Rock
Silicon Dioxide (SiO2) in Rhyolite or Granite matrix
igneous
Gold Ore in Quartz
Native Gold (Au) in Quartz (SiO2)
mineral
Laterite (iron-rich nodule, possibly Bauxite as a subtype)
Laterite (composed of various minerals including goethite, hematite, gibbsite, etc.)
Sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral