Red Jasper (Mahogany Obsidian variant similarity)
Silicon Dioxide (SiO2) with iron oxide inclusions
Category
Browse anthropogenic (man made material) specimens identified by the Rock Identifier community.
Red Jasper (Mahogany Obsidian variant similarity)
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Sandstone
Arenite (predominantly Quartz with Hematite cementation)
Yellow Jasper
Silicon Dioxide with iron inclusions (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Banded Flint (Chert)
Silicon Dioxide (SiO2)
Porphyritic Andesite
Andesite (porphyritic variety)
Sandstone (Red/Brown Variety)
Arenite (SiO2 with iron oxide impurities)
Quartz Geode
Silicon Dioxide (SiO2)
Graphic Granite
Pegmatitic Feldspar with Quartz intergrowths
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Sandstone
Clastic Sedimentary Rock (primarily SiO2)
River Stone / Siltstone
Siltstone (composed of lithified silt)
Chert (Jasper/Ironstone variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Amazonite
Microcline (K(AlSi3O8))
Jasper
Silicon dioxide (SiO2) with impurities
Milky Quartz (Water-worn pebble)
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily SiO2 with various cementing agents)
Fossiliferous Limestone (Coquina / Shell Conglomerate)
Bioclastic Limestone (composed primarily of CaCO3)
Diorite (River Cobble)
Intrusive Igneous Diorite
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Chlorastrolite (Isle Royale Greenstone)
Chlorastrolite (Pumpellyite-(Mg,Fe2+): Ca2MgAl2(Si2O7)(SiO4)(OH)2∙H2O)
Red Sandstone
Arenite (Fe2O3-rich)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite inclusions
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3/FeO(OH) cement)
River Cobble (Quartzite and Iron-stained Quartz)
Quartzite (SiO2 with iron oxide impurities)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Basalt (River Pebble)
Basalt
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Chert (often referred to as 'Jasper' when red)
Chert (microcrystalline quartz, SiO₂)
Chert (Gravel pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
Snakeskin Agate
Agate (Cryptocrystalline Quartz, SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
River Stone (River Pebbles)
Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)