Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Category
Minerals
Browse minerals specimens identified by the Rock Identifier community.
Learn about Minerals in the encyclopedia
View all →
Diorite
Phaneritic plutonic rock (dominated by plagioclase feldspar and hornblende)
igneous
Small quartz-rich mineral fragment
Quartz (SiO₂), possibly milky or chalcedonic quartz
mineral
Shark Tooth Fossil
Chondrichthyes (class) fossilized tooth
fossil
Vesicular basalt (likely scoriaceous basalt)
Basalt, primarily plagioclase + pyroxene ± olivine; iron-oxide staining
igneous
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Milky quartz (possibly quartz-rich pegmatite)
Quartz, silicon dioxide (SiO₂)
mineral
Granite
Coarse-grained felsic intrusive igneous rock; mainly quartz, potassium feldspar, plagioclase, and biotite/hornblende
igneous
Biotite-bearing granite
Granite, composed mainly of quartz (SiO₂), potassium feldspar, plagioclase, and biotite mica
igneous
Greenstone (Epidote/Chlorite Rich Rock)
Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))
metamorphic
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Greenstone with Epidote or Quartz veins
Metabasalt (Greenstone facies)
metamorphic
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Magnetite-rich Basalt
Basalt containing Fe3O4
igneous
Iron-stained weathered volcanic rock (probable basalt/andesite)
Altered basaltic–andesitic rock, chiefly plagioclase and pyroxene with iron oxides/hydroxides
igneous
Weathered iron-rich limestone or marl
Calcitic carbonate rock with limonite/goethite and clay impurities (predominantly CaCO₃)
sedimentary
Quartz and Mixed Sedimentary Rocks
Silicon Dioxide (SiO2) mixed with various clastic sedimentary lithologies
sedimentary
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
metamorphic
Quartz Boulder
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Small Pebble)
Silicon Dioxide (SiO2)
mineral
Granite
Granite
igneous
Quartz pebble
Silicon dioxide (SiO2)
mineral
Quartz (Tumbled)
SiO2 (Silicon Dioxide)
mineral
Quartz (Citrine or Iron-Stained)
SiO2
mineral
Glaucophane-bearing Schist (Blueschist)
Blueschist (Glaucophane-Lawsonite Schist)
metamorphic
Greenstone
Protolith of basalt/gabbro (chlorite-epidote metamorphic facies)
metamorphic
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Limonite Concretion
Goethite-rich Concretion (FeO(OH))
sedimentary
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
sedimentary
Native Sulfur
Sulfur (S)
mineral
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Greenstone
Greenschist (metamorphosed mafic igneous rock)
metamorphic
Geode Nodule Fragment
Quartz / Chalcedony Nodule
sedimentary
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Mineral, often a rock given its aggregate nature
Granite Gneiss
Granitic Gneiss
Metamorphic
Basalt with Epidote (Greenstone)
Amygdaloidal Basalt (Ca2(Al, Fe)3(SiO4)3(OH) inclusions)
igneous