Obsidian
Obsidian (volcanic glass)
Category
Browse man made glass (not a natural rock or mineral) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (volcanic glass)
Shale
Lutaceous Sedimentary Rock
Jasper in Quartz (River Cobble)
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Smoky Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Agate (Polished Nodule)
Agate (Silicon Dioxide, SiO2)
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
Diorite
Diorite (Intermediate intrusive igneous rock)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Quartzite
Quartzite (SiO2)
Sandstone (Quartzose)
Arenite (SiO2 based)
Chert (often called Jasper or River Rock)
Chert (SiO2)
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Pink Granite
Phaneritic intrusive felsic igneous rock
Smoky Quartz (with possible Garnet inclusions)
Silicon Dioxide (SiO2)
Bauxite (Pisolitic Bauxite)
Bauxite (mixture of Hydrous Aluminum Oxides)
Red Sandstone
Arenite (Ferruginous Sandstone)
Collection of Minerals and Ores
Various (e.g., Uraninite (U3O8), Carbon (C), Native Gold (Au), Hematite (Fe2O3), Galena (PbS), etc.)
Smoky Quartz in Matrix
Silicon dioxide (SiO2) within Pegmatite/Gneiss
Sandstone
Arenite (primarily SiO2 with various cementing agents)
Chalk
Carbonate rock (mainly CaCO3)
Smoky Quartz
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Shale
Shale (comprised mostly of clay minerals and quartz)
Raw Citrine
Citrine (Silicon Dioxide - SiO2)
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Granite
Granite (Felsic Plutonic Rock)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Emerald In Matrix
Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium
Citrine Quartz
Silicon Dioxide (SiO2)
Red Quartzite River Pebble
Quartzite (SiO2 with iron oxide inclusions)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Quartz (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Citrine
Citrine (Silicon Dioxide, SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)