Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
SiO2 (Silicon Dioxide)
Ventifact
Eolian Ventifact (often composed of basalt, chert, or quartzite)
Amethyst
Silicon Dioxide with iron impurities (SiO2)
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
Granite
Intrusive igneous rock (Acidic)
Chalk
Calcium Carbonate (CaCO3)
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Citrine Quartz
SiO2 (Silicon Dioxide with Iron impurities)
Ruby in Matrix
Corundum (Al2O3)
Glauconitic Sandstone
Glauconitic Sandstone (Greensand)
Yellow Ochre / Limonite
Limonite (inter-mixed iron oxides and hydroxides, primarily FeO(OH)·nH2O)
Diamond inlaid in Jewelry
Carbon (C)
Sandstone (Quartz-rich)
Arenite (SiO2 based)
Black Onyx
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Sandstone (likely Ferruginous)
Arenite (SiO2 based with Fe2O3/FeO(OH) cement)
Hag Stone
Perforated Chert (Microcrystalline Silica, SiO2)
Coquina
Biogenic Limestone (CaCO3)
Sandstone (Ferruginous)
Arenite (Fe2O3 stained)
Black Pearl (Tahitian Type)
Aragonite / Pinctada margaritifera (CaCO3 + Conchiolin)
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
Magnetite (potentially as a Lodestone or within Ironstone)
Magnetite (Fe3O4)
Diamond (or Cubic Zirconia)
Carbon (C) or Zirconium Dioxide (ZrO2)
Blue Goldstone
Aventurine Glass (Silicon Dioxide with metal inclusions)
Fulgurite
Fulgurite (Lechatelierite-rich variety)
Pyrite Geode
Iron Disulfide (FeS2)
Agate Nodule / Weathered Chert
SiO2 (Silicon Dioxide - Microcrystalline Quartz)
Citrine Quartz Crystal Cluster
Silicon Dioxide (SiO2) with iron impurities
Aura Quartz Geodes (Lab-Altered)
Silicon Dioxide (SiO2) with Metallic Vapor Deposition
Dyed Pink Agate
Silicon Dioxide (SiO2) - variety Chalcedony
Conglomerate
Conglomerate (clastic sedimentary rock)
Diamond
Diamond (Pure Carbon - C)
Dyed Howlite
Borosilicate hydroxide (Ca2B5SiO9(OH)5)
Sandstone (likely Greywacke or Siltstone variety)
Arenite / Siltstone (primarily SiO2)
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
Rough Diamond
Diamond (pure Carbon, C)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si)4O10(F,OH)2)
Amethyst (Chevron Amethyst)
Silicon Dioxide (SiO2) with iron impurities