Agate (Plume/Moss variety)
Cryptocrystalline Quartz (SiO2) with iron/manganese inclusions
Category
Browse mineraloid (man made origin) specimens identified by the Rock Identifier community.
Agate (Plume/Moss variety)
Cryptocrystalline Quartz (SiO2) with iron/manganese inclusions
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
Red Sandstone
Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)
Fluorite
Calcium fluoride (CaF2)
Sandstone (Greywacke)
Clastic Sedimentary Rock (SiO2 with lithic fragments)
Slickenside
Tectonic Fault Scarp Surface
Milky Quartz
Silicon Dioxide (SiO2)
Granite
Phaneritic intrusive igneous rock (consisting mainly of Quartz, Alkali Feldspar, and Plagioclase)
Tiger's Eye (commonly referred to as Blue/Gold Tiger's Eye)
Tiger's Eye is a variety of Chalcedony (cryptocrystalline quartz), SiO2, exhibiting chatoyancy. The blue variety is often called Hawk's Eye.
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Quartz (specifically Milky/White Quartz)
Silicon Dioxide (SiO2)
Banded Iron Formation (BIF) / Tiger Iron
Ferruginous Chert (primarily Quartz [SiO2] and Hematite/Magnetite [Fe2O3/Fe3O4])
Red Quartzite Cobble
Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Hematite (Iron Ore)
Hematite (Fe2O3)
Sandstone (Red Sandstone)
Arenite (primarily Quartz with Hematite cement)
Amber
Succinite (Fossilized Tree Resin)
Granite
Felsic Plutonic Rock (Granite)
Gold Nugget
Native Gold (Au)
Banded River Rock / Gneiss (highly weathered)
Gneiss
Quartz Vein in Host Rock
Hydrothermal Quartz (SiO2) in Slates/Schists
Pink Tumbled Agate
Silicon Dioxide (SiO2) with dye
Chert (Jasper)
Microcrystalline Quartz (SiO2) with Iron Oxide inclusions
Sandstone (Stream-rounded)
Arenite (SiO2 based)
Sandstone
Arenite (primarily Quartz, SiO2)
Prehnite with Epidote inclusions
Prehnite: Ca2Al(AlSi3O10)(OH)2; Epidote: Ca2(Al,Fe)3(SiO4)3(OH)
Petrified Wood
Silicified Wood (primarily SiO₂)
Chert (and its variety Flint)
Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz
Gneiss
Gneiss
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Milky Quartz
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Silicon Dioxide - SiO2)
Granite
Granite (Felsic Plutonic Rock)
Human Skin (Epidermis/Dermis)
Integumentary tissue (High content of hydroxyapatite in bones, though the surface is biological)
Native Copper
Native Copper (Cu)
Diamond
Diamond (C)
Quartz (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)