Greenstone
Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote
Category
Browse metamorphic rock (composed of multiple minerals) specimens identified by the Rock Identifier community.
Greenstone
Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)
Quartzite (Yellow/Orange variety)
Quartzite (primarily SiO2)
Granite
Granite (composed mainly of Quartz, Feldspar, and Mica)
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Garnet Schist
Almandine Garnet-Mica Schist (X₃Y₂(SiO₄)₃)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Boxwork Quartz / Septarian Jasper
Boxwork (SiO2 with iron oxide inclusions)
Blue Quartz (potentially Dumortierite-included)
Silicon Dioxide (SiO2) with inclusions
Peacock Ore (Bornite/Chalcopyrite)
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)
Rough Sapphire (Corundum)
Corundum (Al2O3)
Banded Agate
Agate (Cryptocrystalline variety of Quartz, SiO2)
Blue Sapphire
Corundum (Al2O3)
Granite
Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)
Diorite
Diorite (Intermediate intrusive igneous rock)
Vesicular Basalt with Epidote
Vesicular Basalt (Mg, Fe)2SiO4 with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
Fossiliferous Limestone (Coquina / Shell Conglomerate)
Bioclastic Limestone (composed primarily of CaCO3)
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Sapphirine in Matrix
Sapphirine (Mg,Al)8(Al,Si)6O20
Quartz with Mica inclusions (likely Schist or Gneiss host)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Oolitic Limestone (Egg Stone)
Oolite (Chemical sedimentary rock, primarily CaCO3)
Granite
Phaneritic plutonic rock (SiO2 range 70-75%)
Diorite (Salt and Pepper Rock)
Diorite
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Granite
Phaneritic plutonic rock (approx. 20-60% quartz, 35-90% feldspar)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Yellow Aventurine (Yellow Quartzite)
Silicon Dioxide (SiO2) with inclusions
Rhodonite
Rhodonite (Mn2+SiO3)
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
Schist
Mica Schist
Marble
Recrystallized Calcite / Dolomite (CaCO3)
Red Sandstone
Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Graphite
Graphite (C)
Schist with Quartz Vein
Mica Schist with Crystalline Quartz (SiO2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 oxides)
Banded Agate (Polished Slice)
Chalcedony (cryptocrystalline Quartz), SiO2