Shale
Shale (Lutite)
Category
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
Shale
Shale (Lutite)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Sandstone
Sedimentary Clastic Rock (Quartzose Sandstone)
Diamond (or Simulant)
Carbon (C)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cementation)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 cement)
Quartz Vein in Sandstone
Quartz (SiO2) in Clastic Sedimentary Rock
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Dyed Agate
SiO2
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Sandstone
Arenite (SiO2 based)
Red Sandstone
Sandstone (lithic arenite / ferruginous sandstone)
Sandstone (with Chert/Quartzite)
Arenite (SiO2 primarily)
Amethyst
Amethyst (Silica mineral, SiO2)
Diamond
Diamond (pure Carbon, C)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)
Sandstone
Sedimentary Rock (Quartz Arenite)
Dark mafic igneous rock, likely basalt or gabbro
Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, possibly olivine
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
River Cobble (Quartzite / Granitic Gneiss)
Metamorphic Quartzite / Granitic Gneiss
Weathered iron-rich sandstone or ferruginous siltstone
Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)
Diorite (River Pebble)
Intermediate plutonic igneous rock
Blue Lace Agate
Cryptocrystalline Quartz (SiO2) with trace minerals
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Sandstone (with Laminations)
Clastic sedimentary rock (primarily Quartz-based)
Obsidian
Volcanic Glass (Amorphous SiO2)
Breccia Pebble
Sedimentary Breccia
Red Sandstone
Arenite (Ferruginous Sandstone)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)
Raw Citrine Quartz
Silicon Dioxide (SiO2)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Citrine (Iron-stained Quartz)
Silicon Dioxide (SiO2)
Polished red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
Weathered quartz-rich rock fragment
Likely quartz-bearing feldspathic rock; exact identification requires testing
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
Granodiorite / Granite (Weathered)
Granodiorite
White quartz pebble
Quartz (SiO₂), likely milky quartz
Sandstone
Arenite (SiO2 principal component)
Polished black agate slice
Chalcedony (microcrystalline quartz), SiO₂, with iron/manganese staining