Amethyst Quartz (Chevron Amethyst)
Silicon Dioxide (SiO2) with iron impurities
mineral
Category
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Browse this image does not display a rock, mineral, or geological specimen. it shows a human hand wearing a ring. specimens identified by the Rock Identifier community.
Ruby
Corundum (Al2O3 with Chromium impurities)
mineral
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
mineral
Gold Nugget
Native Gold (Au)
mineral
Amethyst (Quartz)
Amethyst (SiO2 with iron impurities)
mineral
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
igneous
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
igneous
Sandstone
Arenite (SiO2 based)
sedimentary
Calcite (Banded Calcite / Onyx Marble)
Calcium Carbonate (CaCO3)
mineral
Smoky Quartz (Herkimer-style)
Silicon Dioxide (SiO2)
mineral
Orange Quartzite (or Iron-Stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide impurities (Fe2O3)
metamorphic
Quartz
Silicon dioxide (SiO2)
mineral
Ocean Jasper
Spherulitic Chalcedony (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Greasy Quartz (likely carved Milky Quartz or Aventurine)
Silicon Dioxide (SiO2)
mineral
Kyanite
Kyanite (Al2SiO5)
Mineral
Tree Agate (or Moss Agate), faceted into a crystal tower
Dendritic Agate (Silicon Dioxide, SiO2)
Mineral
Obsidian
Obsidian (Volcanic Glass, complex silicate)
igneous
Clear Quartz (Double Terminated)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Pyrite (FeS₂)
Mineral
Dyed Agate (Tumbled)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Crackled Quartz (Blue Dyed)
Silicon Dioxide (SiO2) with anthropogenic dye
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Caliche (with Lichen Cover)
Calcium carbonate-cemented soil layer (CaCO3)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Serpentine
Serpentine Group Minerals (e.g., Antigorite, Chrysotile, Lizardite)
Mineral, often found as a rock
Indigo Gabbro (also known as Mystic Merlinite)
Gabbro (composed of Plagioclase Feldspar, Pyroxene, and minor Magnetite/Ilmenite)
igneous
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
igneous
Granite
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8, and Mica)
Igneous
Sodalite-rich Syenite (Yooperlite)
Sodalite-rich Syenite (Na8(Al6Si6O24)Cl2 within an igneous matrix)
igneous
Quartz (Milky/Crystal Variety)
Silicon Dioxide (SiO2)
mineral
Red Quartzite
Quartzite (SiO2)
metamorphic