Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Category
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Greenstone / Greenschist
Greenschist facies metamorphic rock
Limonite Concretion
FeO(OH)qnH2O (Hydrated iron(III) oxide-hydroxide mixture)
Diamond (in jewelry setting)
Carbon (C)
Amygdaloidal Rhyolite (often called Lake Superior Agate relative)
Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)
Banded Sedimentary Rock
Sedimentary rock with Liesegang banding
Jasper and Mudstone Composite
Silicified Sedimentary Rock / Jasperoid Pebble
Limonite and Goethite
Limonite (hydrated iron(III) oxide-hydroxide) and Goethite (α-FeO(OH))
Banded Gneiss Pebble
Banded Gneiss
Chert / Flint (with quartz or calcite inclusion)
Silicon dioxide (SiO2)
Weathered volcanic rock, likely andesite
Andesite (plagioclase–pyroxene volcanic rock), identification tentative
Yellow Quartz (Citrine or Yellow Jasper)
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Limonite Boxwork / Iron Ore Concretion
FeO(OH)qnH2O (Hydrated iron oxide)
Limonite / Ironstone Nodule
Hydrated Iron Oxide (FeO(OH)·nH2O)
Druzy Quartz on Sandstone
Silicon Dioxide (SiO2) on Sedimentary Host Rock
K2 Jasper
Azurite in Granite
Amethyst
Crystalline Silicon Dioxide with Iron impurities (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Limonite or Ironstone Nodule
Hydrated iron oxide-hydroxide (FeO(OH)·nH2O)
Amazonite
K(AlSi3O8) (Microcline Feldspar)
Tumbled Agate
Silicon Dioxide (SiO2)
Banded Agate (Tumbled)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2)
Agate (Chalcedony)
Silicon Dioxide (SiO2)
Limonite (Iron Stone/Goethite)
Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))
Banded Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Basalt with vesicles (Amygdaloidal Basalt)
Amygdaloidal Basalt (predominantly Plagioclase and Pyroxene)
Vesicular basalt (likely scoria)
Vesicular basalt; predominantly plagioclase, pyroxene, and Fe-Mg oxides
Yellow Sapphire (Corundum)
Corundum (Aluminum Oxide, Al2O3)
Yellow Sapphire
Corundum (Al2O3) with iron impurities
Blue Sapphire
Corundum (Al2O3)
Yellow Quartz (Chert/Chalcedony)
Silicon Dioxide (SiO2) with iron inclusions
Gneiss
Gneissic Metamorphic Rock
Gneiss
Gneiss
Banded metamorphic rock, likely gneiss
Foliated gneiss; chiefly quartz, feldspar, and dark mica/amphibole
Gneiss (with Quartz and Biotite Mica)
Gneiss
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
Limonite
FeO(OH)·nH2O
Quartz (Iron-stained)
Silicon Dioxide (SiO2)