Gneiss
Foliated Metamorphic Gneiss
Category
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Gneiss
Foliated Metamorphic Gneiss
Gneiss
Gneiss
Basalt
Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)
Pink Granite (Unakite-bearing or Epidote-bearing Granite)
Plutonic Igneous Rock (Granite)
Quartz Geode
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Goethite (Iron Ore)
Goethite (FeO(OH))
Bronzite
Enstatite (var. Bronzite), (Mg,Fe)SiO3
Pink Granite
Plagioclase-Quartz-K-Feldspar Granite
Amygdaloidal Rhyolite
Amygdaloidal Rhyolite (Felsic volcanic rock)
Chalcedony
Silicon dioxide (SiO2) - Microcrystalline quartz
Agate
Silicon Dioxide (SiO2)
Limonite (with Goethite/Ironstone)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Yellow Aventurine
Quartz with inclusion minerals (SiO2)
Basalt
Mafic Extrusive Igneous Rock
Sandstone Pebble
Arenite (SiO2 based)
Diamond
Native Carbon (C)
Snowflake obsidian cabochon
Obsidian (volcanic glass), SiO₂-rich; white areas are cristobalite/spherulitic devitrification
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Agate (Puddingstone style)
Silicon Dioxide (SiO2) with impurities
Jasper Agate
Chalcedony (Silicon Dioxide - SiO2)
Yellow Quartz (Chalcedony)
Silicon Dioxide (SiO2)
Beach Agate (Chalcedony)
Silicon Dioxide (SiO2)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Black Limestone with Calcite Veins
Carboniferous Limestone with Secondary Calcite Infill
Moss Agate
SiO2 (Silicon Dioxide) with dendritic inclusions
Amethyst (Geode)
Silicon Dioxide (SiO2) with iron impurities
Vesicular Basalt
Vesicular Basalt (Aphanitic Mafic Igneous Rock)
Rose Quartz
Quartz (Silicon Dioxide - SiO2)
Moonstone (Feldspar)
Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8)
Rose Quartz
Silicon dioxide (SiO2)
Sandstone Concretion
Sedimentary Concretion (Quartz sand bound by mineral cement)
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Shale with Iron Staining
Fissile Argillaceous Sedimentary Rock
Basalt with Epidote
Mafic volcanic rock with Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with trace Iron (Fe)
Diamond
Diamond (Carbon, C)
Copper Ore (Chrysocolla/Malachite in host rock)
Hydrated copper phyllosilicate and copper carbonate hydroxide
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
Banded Gneiss
Gneiss (Metamorphic rock)