Vesicular quartz-rich rock, possibly weathered rhyolite or silicified volcanic breccia
Silica-rich volcanic rock; likely microcrystalline quartz (SiO₂) with altered feldspar and iron-oxide staining
Category
Browse mineralogical specimen specimens identified by the Rock Identifier community.
Vesicular quartz-rich rock, possibly weathered rhyolite or silicified volcanic breccia
Silica-rich volcanic rock; likely microcrystalline quartz (SiO₂) with altered feldspar and iron-oxide staining
Unidentified gray rock/mineral specimen
Indeterminate; possibly quartz-rich rock or a metallic sulfide-bearing specimen
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Carnelian Agate
Silicon Dioxide (SiO2) - Variety: Chalcedony
Zoisite with Rubellite (Ruby in Zoisite)
Zoisite with inclusions of Hornblende (Anyolite)
Carnelian
SiO2 (Silicon Dioxide)
Chert Breccia
Brecciated Chert (Microcrystalline SiO2)
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
Quartz (Milky/Crystalline)
Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Jasper Agate
Silicon dioxide (SiO2)
Flint (or Chert)
Microcrystalline quartz (SiO2)
Chert (Sea-worn Pebble)
Microcrystalline Quartz (SiO2)
Chalcedony (Agate/Jasper mix)
Cryptocrystalline Quartz (SiO2)
Quartz Mineral
Silicon Dioxide (SiO2)
Agate Geode Slice (with Druzy Quartz)
Silicon Dioxide (SiO2)
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
Feldspar (likely Amazonite or Plagioclase)
Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate
Granite (likely biotite granite)
Coarse-grained felsic plutonic rock: quartz + feldspar + biotite; approximate composition SiO₂-rich
Unidentified dark pebble
Undetermined; possibly polished basalt, chert, or iron-rich stone
Pyrite with Vesicular Matrix
Iron Disulfide (FeS2)
Chert (Banded)
Cryptocrystalline Silica (SiO2)
Quartz (specifically a water-worn Quartzite or Chalcedony pebble)
Silicon Dioxide (SiO2)
Quartz (White/Milky with Iron Staining)
Silicon Dioxide (SiO2)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70-75% SiO2)
Labradorite
(Ca, Na)(Al, Si)4O8
Undetermined Due to Blur (Possible Flesh-Tone Mineral)
Unknown (Insufficient Visual Clarity)
Limonite
FeO(OH)•nH2O
Yellow Quartz or Citrine Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Diamond
Carbon (C)
Diamond
Natural Carbon (C)
Diamond (in jewelry setting)
Carbon (C)
Cubic Zirconia (in Jewelry)
Zirconium Dioxide (ZrO2)
Brecciated Jasper
SiO2 (Silicon Dioxide)
Granite
Granite (Phaneritic Quartz-Feldspar rock)
Quartz Geode in Sedimentary Host Rock
Silicon Dioxide (SiO2) in Carbonate Matrix
Orange Quartz
Silicon Dioxide (SiO2)
Granitic Pegmatite (with Smoky Quartz and Mica)
Granitic Pegmatite (composed of SiO2, KAl2(AlSi3O10)(OH)2, and (K,Na)(AlSi3O8))
Chalcedony on Ironstone
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3/FeOOH)
Limonite
FeO(OH)·nH2O