Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
mineraloid
Category
Sedimentary And Igneous (Mixed)
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix
igneous
Magnetite
Magnetite (Fe3O4)
Mineral
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Chlorite or Actinolite
sedimentary
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
White Agate (Chalcedony)
Chalcedony (SiO2)
mineral
Carnelian
Carnelian (Silicon Dioxide, SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Garnet (Almandine/Pyrope variety)
Silicate mineral group; typically Fe3Al2(SiO4)3 (Almandine) or Mg3Al2(SiO4)3 (Pyrope)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Gneiss
Gneiss
metamorphic
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Biotite Mica
K(Mg, Fe)3AlSi3O10(F, OH)2
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Magnetite (likely with weathered Limonite/Hematite)
Magnetite (Fe3O4) with iron oxide weathering
mineral
Rhodolite Garnet
Magnesium Aluminum Silicate; formula: (Mg,Fe)3Al2(SiO4)3
mineral
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Quartz Geode
Silicon dioxide (SiO2)
mineral
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Gneiss (Cobble)
Gneiss
metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Pyrite (on Quartz matrix)
Iron Sulfide (FeS2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Hematite
Iron(III) oxide (Fe2O3)
mineral
Quartz (Grain/Fragment)
Silicon Dioxide (SiO2)
mineral
Quartz (specifically Milky or Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral