Shale (or Slate / Coal / Jet)
Laminated fine-grained sedimentary rock (predominantly clay minerals)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Shale (or Slate / Coal / Jet)
Laminated fine-grained sedimentary rock (predominantly clay minerals)
Glauconitic Sandstone
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Quartzite Cobble
Quartzite (principally SiO2)
Green Glass Slag
Amorphous Silicon Dioxide (SiO2) with metal oxide impurities
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Quartzite
Quartzite (SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Limestone
Calcium Carbonate (CaCO3)
Amber
Succinite (C10H16O)
Amber
Succinite (Formula: C10H16O)
Amber (Butterscotch/Egg Yolk Variety)
Succinite (Approx. C10H16O)
Chert with Quartz Veins
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
Chert Nodules
Chert (SiO2)
Quartzite Pebble
Quartzite
Obsidian
Obsidian (Amorphous volcanic glass)
Quartzite
Metamorphic Quartzite (SiO2-rich rock)
Fossiliferous Sedimentary Rock
Sedimentary Rock with Invertebrate Fossil Imprint
River Rock (Quartzite)
Quartzite (SiO2)
Quartzite Pebble
Quartzite (SiO2)
Likely blue glass or synthetic gemstone jewelry
Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass
Quartzite Pebble
Quartzite (SiO2)
Chert (Pebble)
Microcrystalline Quartz (SiO2)
Vuggy Limestone
Carbonate Sedimentary Rock with Vuggy Porosity (CaCO3)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Black Jasper
Silicon dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert Arrowhead (Lithic Tool)
Microcrystalline quartz (SiO2) - Archeological lithic artifact
Fossiliferous Limestone
Carbonate sedimentary rock (CaCO3) with bioclasts
Chert Nodule (with Geode cavity)
Cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
White Marble
Metamorphic carbonate rock (primarily CaCO3)
Greenstone (Celadonite-bearing Volcanic)
Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
Quartzite (Orthoquartzite)
SiO2 (Silicon Dioxide) with Iron Oxide inclusions
Sandstone
Sandstone (SiO2 predominant)