Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
Ruby
Corundum (Al2O3 with Chromium traces)
Silver (Native Silver)
Native Silver (Ag)
Diamond (Princess Cut Faceted Gemstone)
Native Carbon (C)
Diamond
Diamond (Pure Carbon, C)
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4
Quartz Cobble (with Iron Staining)
Silicon Dioxide (SiO2)
Anthracite Coal
Anthracite
Quartzite Pebbles
Quartzite (SiO2)
Jasper (Milky/Cream Variety)
Silicon Dioxide (SiO2) - variety of Chalcedony
Anthracite
Anthracite Coal (C)
Marble
Recrystallized Calcite Rock (CaCO3)
Tiger's Eye (variations include Blue or Hawk's Eye)
Silicon Dioxide with Crocidolite inclusions (SiO2)
Chert (often called Jasper or Flint in this color variety)
Silicon Dioxide (SiO2)
Coarse Sand Grain / Lithic Fragment
Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)
Anthracite Coal
Anthracite
Quartz (Tumbled/Polished Pebble)
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chrysocolla
Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O
Granitic Pegmatite
Granite Pegmatite (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Muscovite)
Schist (with Iron Oxide)
Mica Schist
Pumice
Vesicular Rhyolite / Pumice
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
Schist (Micaceous Schist)
Schist (containing mainly Muscovite and Quartz)
Sandstone (Yellow/Tan Sandstone)
Arenite (primarily Quartz, SiO2)
Bauxite
Bauxite (mixture of Gibbiste Al(OH)3, Boehmite ̳-AlO(OH), and Diaspore ́-AlO(OH))
Ruby in Matrix
Corundum (Al2O3)
Quartzite
Quartzite (SiO2)
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
Kimberlite with Diamond
Kimberlite (Diamond formula: C)
Ferruginous Quartz (River Pebble)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Diamond (set in Gold)
Carbon (C)
Diamond (in Jewelry Setting)
Carbon (C) - Isometric-Hexoctahedral
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Quartz Geode (Cracked Open Fragment)
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)