Sandstone (Iron-stained)
Clastic sedimentary rock (SiO2 with Fe2O3 staining)
Category
Browse igneous or metamorphic (base stone); anthropogenic (decoration) specimens identified by the Rock Identifier community.
Sandstone (Iron-stained)
Clastic sedimentary rock (SiO2 with Fe2O3 staining)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite on Quartz (Fool's Gold in Quartz)
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Pyrite (on a metal substrate)
Iron Sulfide (FeS2)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Smoky Quartz
SiO2 (Silicon Dioxide with aluminum impurities)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Emerald
Beryl (Be₃Al₂(SiO₃)₆) with Chromium or Vanadium impurities
Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Quartz Pebble (Citrine-colored or Stained Quartz)
Silicon Dioxide (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Amethyst and Hematite Bracelet
Amethyst (SiO2) and Hematite (Fe2O3)
Unidentified Rock Fragment
Unknown
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with Iron Oxide impurities
Pyrite
Iron Disulfide (FeS2)
Citrine (Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
Basalt
Basalt
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Chert (and Quartz Gravel)
Chert (Cryptocrystalline Quartz, SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace titanium, iron, or manganese
Gneiss (specifically Granitic Gneiss)
Gneissic Metamorphic Rock
Quartzite
Quartzite (SiO2)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate Hydroxide; NaFe2+3Al6Si6O18(BO3)3(OH)3OH
Orange Quartzite / Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions
Tiger's Eye (Inlaid in a band)
SiO2 (Silicon Dioxide with Crocidolite inclusions)
Coquina
Coquina (Biogenic Limestone / CaCO3)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz - SiO2)
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
Quartz
Silicon Dioxide (SiO2)
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Dendritic Agate (also known as Dendritic Siltstone or Mudstone)
Silicon Dioxide with Manganese/Iron Oxide inclusions (SiO2 + MnO2)
Rhodonite
Rhodonite (Mn, Fe, Mg, Ca)SiO3
Gneiss
Gneiss (High-grade metamorphic rock)
Limestone (specifically a Crushed Aggregate fragment)
Calcium Carbonate (CaCO3)
Unakite
Epidotized Granite (composition: K-feldspar, Epidote, and Quartz)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)