Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Category
Browse amorphous solid specimens identified by the Rock Identifier community.
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
White Agate (Chalcedony)
Agate (Silicon Dioxide - SiO2)
Black Onyx
Cryptocrystalline Quartz (SiO2 with organic/iron impurities)
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Garnet-bearing Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
Limestone
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Quartz Geode
Macrocrystalline Quartz (SiO2) within a geode structure
Schist
Mica Schist (Medium-grade metamorphic rock)
Gold Nugget
Native Gold (Au)
Limonitic Scoria (Vesicular Basalt with Iron Staining)
Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]
Petrified Wood
Silicified Wood
Petrified Wood
Silicified Wood (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite (specifically an iron-stained or Carnelian-colored variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Lapis Lazuli (Low Grade)
Lapis Lazuli (Metamorphic rock containing lazurite, calcite, and pyrite)
Composite Turquoise or Reconstituted Turquoise with Copper inclusions
CuAl6(PO4)4(OH)8·4H2O (Turquoise) mixed with matrix and copper/bronze flakes
Geode (Quartz / Chalcedony Geode)
Silicon Dioxide (SiO2) - Quartz / Chalcedony
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety
Geode (Quartz)
Silicon Dioxide (SiO2)
Dyed Crackle Quartz
Silicon Dioxide (SiO2) with synthetic dye
Black Onyx
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (quartz-feldspar-biotite metamorphic rock)
Petrified Wood
Silicified Wood (SiO2)
Black Onyx
Silicon Dioxide (SiO2) - variety of Chalcedony
Quartzite Pebble (River Rock)
Metamorphic Quartzite (predominantly SiO2)
Dendritic Jasper
SiO2 (Microcrystalline Quartz)
Chert breccia
Sedimentary Breccia (Microcrystalline Quartz)
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) with iron and other impurities
Bronzite
MgSiO3 (Enstatite with 10-30% FeSiO3 in solid solution)
Black Onyx
Silicon Dioxide (SiO2)
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pink Quartzite
Quartzite (primarily SiO2)
Ruby in Fuchsite
Corundum (Al2O3) in Chrome-Mica (K(Al,Cr)2(AlSi3O10)(OH)2)
Quartz Geode
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (Permineralized wood)
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Petrified Wood
Silicified Wood (SiO2)
Quartzite
Quartzite (SiO2)
Sandstone (Pebble)
Sandstone (SiO2 dominated with minor feldspar/clay)