Gneiss
Gneissic Metamorphic Rock
Category
Browse mineral on igneous rock specimens identified by the Rock Identifier community.
Gneiss
Gneissic Metamorphic Rock
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Yellow Quartz (Citrine-colored Quartz Pebble)
Silicon Dioxide (SiO2)
Granite
Phaneritic Intrusive Igneous Rock (primarily Quartz, Feldspar, and Mica)
Greenschist
Greenschist facies rock (containing chlorite, actinolite, and epidote)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Granite
Phaneritic Felsic Igneous Rock (Granite)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Basalt
Vesicular Basalt
Basalt
Basalt (composition predominately Plagioclase feldspar and Pyroxene)
Granite
Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Sodalite (blue beads) and Clear Quartz (clear beads)
Sodalite: Na4Al3Si3O12Cl; Quartz: SiO2
Dalmatian Stone
Peralkaline Quartz-Feldspar Rock
Granite
Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)
Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Granitic Gneiss
Gneiss (High-grade Metamorphic Rock)
Diorite
Diorite (Intermediate plutonic rock)
Polished Basalt
Basalt (Mafic volcanic rock)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Basalt River Stone
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) in Rhyolitic Matrix
Citrine
Citrine (Silicon Dioxide - SiO2)
Basalt (River Pebble)
Extrusive Magic Igneous Rock (Mainly Plagioclase and Pyroxene)
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
Granite Pebble
Granite (Phaneritic Quartz-Feldspar Rock)
Basalt
Extrusive Mafic Igneous Rock
Basalt (Road Aggregate / Crushed Stone)
Aphanitic Mafic Igneous Rock
Diabase (Greenstone)
Diabase (also known as Dolerite)
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Granite
Granite (Phaneritic Igneous Rock)
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)