Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Category
Man Made Material, Not A Natural Rock Or Mineral Specimen
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Cullet Glass (Industrial Slag Glass)
Amorphous Silica (SiO2) with metallic oxide impurities
Man-made byproduct (often mistaken for Obsidian or Emerald)
Granite (Pegmatitic)
Phaneritic Felsic Igneous Rock
igneous
Diamond in Kimberlite
Diamond (C in Kimberlite)
igneous
Geode with Quartz/Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
sedimentary
Sandstone
Arenite/Quartz Arenite
sedimentary
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
mineral
Sandstone
Arenite (primarily SiO2 with various cementing agents)
sedimentary
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Banded Agate (specifically Botswana Agate or Water-line Agate)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Sandstone with Quarzite clasts
Arenite (SiO2 based)
sedimentary
Blue Slag Glass
Amorphous Silica (Byproduct of smelting)
Antropogenic (Man-made)
Sandstone (likely Siltstone or fine-grained Sandstone)
Sedimentary Rock (Clastic)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Sandstone (likely Greywacke or Lithic Sandstone)
Arenite / Wacke
sedimentary
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Sandstone
Arenite (SiO2 based with quartz, feldspar, or lithic fragments)
sedimentary
Sandstone (Quartzose Sandstone)
Clastic Terrigenous Sedimentary Rock (primarily SiO2)
sedimentary
Granite Pebble
Granite; primarily composed of Quartz (SiO2), Feldspar (KAlSi3O8), and Mica
igneous
Rough Diamond
Diamond (Native Carbon, C)
mineral
Quartz (Milky/Crystalline)
Silicon Dioxide (SiO2)
mineral
Chert (Holey Stone)
Microcrystalline Quartz (SiO2)
sedimentary
Granite (Weathered River Rock)
Plutonic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (Quartzose)
Arenite (SiO2 based)
sedimentary
Ocean Jasper
Orbicular Jasper (Silicon Dioxide with impurities), SiO2
mineral
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Anthropogenic (Man-made product subject to geological processes)
Silicon Carbide (Carborundum)
Silicon Carbide (SiC)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 impurities)
sedimentary
Granite (Leucogranite)
Felsic Plutonic Rock (Granite)
igneous
Blue Goldstone
Aventurine Glass
Man-made glass (often grouped with minerals in lapidary)
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
sedimentary
Breciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Cobble (Quartzite)
Meta-orthoquartzite
metamorphic