Specular Hematite and Magnetite Ore
Iron Oxide (Fe2O3 and Fe3O4)
mineral
Category
Sedimentary (Secondary Mineral Formation)
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Garnet (likely Almandine or Pyrope)
Garnet Group, Nesosilicates (Complex chemistry, e.g., Almandine: Fe3Al2Si3O12)
mineral
Blue Tiger's Eye (Hawk's Eye)
Silicified Crocidolite (Silicon Dioxide with inclusions of Crocidolite), SiO2
Mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Limonitic Quartzite
Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining
metamorphic
Granite
Phaneritic Felsic Intrusive Rock
igneous
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
mineral
Granite (likely a river or beach pebble)
Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)
Igneous
Quartzite
Quartzite (SiO2)
metamorphic
Black Tourmaline (Schorl)
Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
mineral
Lace Agate (specifically Red Lace Agate)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Mineral
Rutilated Quartz (beads)
SiO2 with TiO2 inclusions (Titanium Dioxide inclusions within Quartz)
Mineral
Granite
Granite (a common rock type, not a single mineral species)
Igneous
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
igneous
Specular Hematite
Hematite (Iron Oxide, Fe2O3)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
mineral
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium or Manganese
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
White Quartz
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
mineral
Watermelon Tourmaline in Quartz Matrix
Elbaite (complex Borosilicate) - Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
mineral
Sandstone (Quartzite-rich)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Blue Quartzite
Quartzite (specifically a variety enriched with blue-coloring minerals)
Metamorphic Rock
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Geode (partially formed/chalcedony with iron staining)
Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides
Mineral/Sedimentary Rock Feature
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
igneous
Tiger's Eye
Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz
Mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
Igneous
Chondrite Meteorite
L3 Chondrite (Unequilibrated Ordinary Chondrite)
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron oxide impurities
sedimentary (chemical)
Granite
Intrusive Phaneritic Felsic Igneous Rock
igneous
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)
Iron-stained Quartzite
Quartzite with Limonite/Hematite staining (SiO2 with FeO(OH)·nH2O)
metamorphic
Quartzite with Iron Staining
Quartzite (primarily SiO2 with Fe2O3 staining)
metamorphic
Granite
Granite (a felsic intrusive igneous rock)
Igneous Rock