Epidote
Ca2(Al,Fe)3(SiO4)3(OH)
mineral
Category
Sedimentary Or Metamorphic (Low Grade)
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Learn about Sedimentary Or Metamorphic (Low Grade) in the encyclopedia
View all →
Likely weathered sandstone or metasandstone
Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)
sedimentary
Slate
Metamorphic pelitic rock
metamorphic
Slate
Foliated Metamorphic Rock
metamorphic
Foliated metamorphic rock, likely schist
Mica schist or chlorite schist; composition commonly quartz + mica/chlorite ± feldspar
metamorphic
Slate
Slate; predominantly fine-grained phyllosilicates, commonly muscovite/illite and chlorite with quartz
metamorphic
Biotite Schist
Metamorphic Rock (Schist)
metamorphic
Likely blue-green schist
Chlorite–epidote schist (tentative visual identification)
metamorphic
Weathered gray slate or phyllite pebble
Fine-grained, foliated metamorphic rock; exact identification requires closer examination
metamorphic
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Weathered iron-rich rock, likely shale or slate
Probably ferruginous shale (iron-oxide-stained mudstone); exact identification requires testing
sedimentary
Green Slate (Greenstone)
Foliated Metamorphic Rock (rich in Chlorite/Epidote)
metamorphic
Slate
Foliated Metamorphic Rock
metamorphic
Slate
Slate (Metamorphic Rock)
metamorphic
Greenschist
Greenschist (composed mainly of chlorite, epidote, actinolite, and albite)
metamorphic
Pyrite in Slate
Iron Disulfide (FeS2) in Low-grade Metamorphic Rock
metamorphic
Slate
Foliated metamorphic rock (Slate)
metamorphic
Greenstone
Metamorphic mafic rock
metamorphic
Weathered dark shale or slate-like rock
Fine-grained argillaceous rock; exact identification requires examination of a fresh surface
sedimentary
Slate with Iron Staining
Low-grade Metamorphic Mudstone (Slate)
metamorphic
Banded gneiss pebble
Gneiss, typically quartz–feldspar–mica assemblage
metamorphic
Anthracite Coal
Anthracite (Metamorphic/High-grade Coal)
sedimentary
Likely blue-gray slate
Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz
metamorphic
Slate
Metamorphic Pelitic Rock
metamorphic
Slate
Metamorphosed pelitic shale
metamorphic
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Slate
Metamorphic Pelitic Rock
metamorphic
Gray slate or fine-grained metamorphic rock
Slate–phyllite spectrum; predominantly fine-grained quartz, mica, and chlorite
metamorphic
Carnelian
SiO2 (Silicon Dioxide with Iron Oxide impurities)
gemstone
Grey Slate
Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)
metamorphic
Greenstone (Greywacke or Nephrite Jade variant)
Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)
metamorphic
Slate
Foliated low-grade metamorphic rock
metamorphic
Greenschist
Greenschist (composed mainly of actinolite/tremolite, chlorite, and epidote)
metamorphic
Garnet
Garnet group: X3Y2(SiO4)3 (commonly Almandine-Pyrope series)
mineral
Greenschist
Greenschist (Major minerals include Chlorite, Actinolite, and Epidote)
metamorphic
Epidote (Unakite component) / Green Quartzite
Ca2(Al,Fe)3(SiO4)3(OH)
metamorphic
Slate
Slate (Low-grade metamorphism of shale/mudstone)
metamorphic
Fine-grained, foliated rock (possibly slate or phyllite)
Undetermined; likely slate or phyllite, composed mainly of quartz, mica, and chlorite
metamorphic
Slate
Slate; predominantly fine-grained phyllosilicates (muscovite/illite, chlorite) with quartz and feldspar
metamorphic
Spessartine Garnet in Quartz/Feldspar Pegmatite
Spessartine (Mn3Al2(SiO4)3) in Quartz (SiO2) and Feldspar
Mineral in Igneous Rock
Blue Kyanite
Kyanite (Al2SiO5)
mineral