Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Category
Browse not a geological specimen specimens identified by the Rock Identifier community.
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Amazonite
Microcline (KAlSi3O8) with Pb impurities
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2 with Fe impurities)
Red Jasper
Silicon Dioxide (SiO2) - variety Jasper
Thunderegg
Agate-filled Rhyolitic Nodule (SiO2)
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
Amethyst Geode
Silicon dioxide (SiO2) with iron impurities
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Amazonite
KAlSi3O8 (Potassium aluminum silicate - blue-green variety of Microcline)
Sunstone
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Arfvedsonite in Quartz
Arfvedsonite [Na3(Fe2+4Fe3+)Si8O22(OH)2] often hosted in Quartz or Feldspar
Amazonite
Potassium Aluminum Silicate (KAlSi3O8)
Olivine in Basalt
Peridotite / Forsterite ((Mg,Fe)2SiO4)
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
Agate
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe3+)
Moonstone (specifically Rainbow Moonstone / White Labradorite)
White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)
Quartz (Milky and Smoky variety)
Silicon Dioxide (SiO2)
Chert / Chalcedony (likely carnelian or flint variety)
Silicon Dioxide (SiO2)
Granitic Quartz with Feldspar
Granite (composed primarily of SiO2 and KAlSi3O8)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Liesegang Banded Sandstone (Wonderstone)
Ferruginous Sandstone with Liesegang Rings
Porphyritic Andesite
Andesite (porphyritic variety)
Jasper in Quartz (River Cobble)
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Quartz (Citrine or Smoky variant)
Silicon Dioxide (SiO2)
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Quartzite Pebble
Recrystallized Quartz (SiO2)
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety
Quartz Vein in Metamorphic Rock
Silicon Dioxide (SiO2) within Metasedimentary host
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Titanium Quartz (Rough)
Titanium-included Silicon Dioxide (SiO2 + Ti)
Banded Calcite (often sold as Onyx Marble)
Calcite (Calcium Carbonate, CaCO3)
Quartzite Pebble
Quartzite (primarily SiO2)
Tanzanite (Rough)
Blue Zoisite (Ca2Al3(SiO4)3(OH))
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Tektite (Indochinite)
Tektite (Amorphous Meteoritic Glass)
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Petrified Wood
Silicified Wood (SiO2)
Yellow Jasper
Jasper (Silica-rich Microcrystalline Quartz, SiO2 with Iron impurities)