Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)
Gneiss (complex silicate composition)
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)
Gneiss (complex silicate composition)
Yellow Agate
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Sodalite
Na8(Al6Si6O24)Cl2
River Quartz Cobble
Silicon Dioxide (SiO2)
Potassium Feldspar and Quartz
KAlSi3O8 (Potassium Feldspar) and SiO2 (Quartz)
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
Dalmatian Stone (often misnamed Dalmatian Jasper)
Aplite (with hornblende/arfvedsonite inclusions)
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
Granite Pebble
Granite (composed primarily of Quartz, Feldspar, and Mica)
Pink Feldspar
Orthoclase Feldspar (KAlSi3O8)
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
Pyrite
Iron Sulfide (FeS2)
Green Calcite
Calcium Carbonate (CaCO3)
Hematite (Iron Ore)
Hematite (Fe2O3)
Arfvedsonite in Quartz (also known as Eudialyte/Garnet Syenite variety)
Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2] within a silicate matrix
Blue Apatite
Apatite-(CaF), Ca5(PO4)3F
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Garnet (Almandine/Pyrope series)
Silicate mineral (Almandine: Fe3Al2Si3O12; Pyrope: Mg3Al2Si3O12)
Green Quartz (Prasiolite/Adventurine)
Silicon Dioxide (SiO2) with inclusions
Blue Lace Agate
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe3+)
Granite
Granite
Epidote with Magnetite/Hematite inclusions
Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides
Moonstone with Black Tourmaline
Orthoclase (KAlSi3O8) with Schorl inclusions
Quartz (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Basalt with Epidote (Flowerstone-like texture)
Amygdaloidal Basalt (silicate mineral inclusions)
Quartz on Matrix
Silicon Dioxide (SiO2)
Granite
Plutonic felsic igneous rock
Granite Pegmatite with Tourmaline and Muscovite
Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
Granite
Granite (a common rock type, not a single mineral; composed primarily of Quartz, Feldspar (Orthoclase and Plagioclase), and Mica (Biotite and/or Muscovite) and/or Amphibole)
Milky Quartz
Silicon Dioxide (SiO2)
Basalt with Quartz Vein
Basalt (SiO2 vein inclusion)
Fluorite
Calcium Fluoride (CaF2)
Pyrite (Iron Pyrites)
Iron Sulfide (FeS2)