Banded gneiss (possibly migmatitic gneiss)
Quartz–feldspar–mica gneiss; composition commonly includes quartz, feldspar, biotite/hornblende, and accessory dark minerals
metamorphic
Category
Igneous And Sedimentary
Browse igneous and sedimentary specimens identified by the Rock Identifier community.
Learn about Igneous And Sedimentary in the encyclopedia
View all →
Banded gneiss pebble
Gneiss, a foliated metamorphic rock composed mainly of quartz, feldspar, and mica or amphibole
metamorphic
Polished banded gneiss
Biotite–quartz–feldspar gneiss, locally migmatitic
metamorphic
Foliated Gneiss (River-Worn Pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Feldspathic Gneiss
Feldspathic Gneiss (High-grade regional metamorphic rock)
metamorphic
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
sedimentary or igneous
Banded Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
Quartz–feldspar–mica gneiss
metamorphic
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Mineral
Blue-dyed Quartz Druzy
Silicon Dioxide (SiO2) with artificial pigment
mineral
Amethyst
Amethyst (SiO2 - Silicon Dioxide with iron impurities)
mineral
Gneiss
Foliated Metamorphic Rock (Gneiss)
metamorphic
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded gneiss pebble
Gneiss, commonly quartz–feldspar–mica gneiss
metamorphic
Banded gneiss or banded metamorphic rock
Gneiss, likely quartz–feldspar–biotite gneiss
metamorphic
Gneiss with Quartz Vein
Gneiss (containing SiO2 vein)
metamorphic
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded gneiss, possibly garnet-bearing
Foliated gneiss; predominantly quartz–feldspar–mica, with possible amphibole or garnet
metamorphic
Banded gneiss pebble
Biotite–quartz–feldspar gneiss (composition variable)
metamorphic
Banded gneiss
Gneiss, commonly quartz–feldspar–mica gneiss
metamorphic
Banded Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Polished banded gneiss or amphibolite specimen
Biotite–quartz–feldspar gneiss, possibly amphibole-rich; exact identification requires testing
metamorphic
Agate Geode
Chalcedony (SiO2 - Silicon Dioxide)
sedimentary (secondary mineral formation)
Gneiss (specifically a weathered or stream-worn specimen)
Gneiss (Foliated Metamorphic Rock)
metamorphic
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Gneiss
Metamorphic Gneiss
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)
metamorphic
Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
metamorphic
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
metamorphic
Weathered gneissic metamorphic rock
Gneiss, likely quartz–feldspar–mica gneiss
metamorphic
Pyrite
Pyrite (FeS₂)
Mineral
Banded gneiss with amphibolite and granitic rocks
Gneiss, commonly quartz–feldspar–biotite gneiss; associated amphibolite and granite
metamorphic
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Pink Opal / Peruvian Opal
Hydrated amorphous silicon dioxide (SiO2·nH2O)
Mineral
River Stone (Basalt or Siltstone with banding)
Polished Basaltic or Siliciclastic River Cobble
igneous or sedimentary
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
igneous and sedimentary
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Ruby in Zoisite
Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende
Metamorphic Rock (composed of multiple minerals)