Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Category
Metamorphic Or Igneous Alteration
Browse metamorphic or igneous alteration specimens identified by the Rock Identifier community.
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
metamorphic
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
sedimentary or metamorphic
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix
metamorphic
Banded River Rock / Gneiss (highly weathered)
Gneiss
Metamorphic rock
Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)
Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)
Metamorphic
Jasper, Agate, Quartz Mix (Polished Beads)
SiO₂ (Silicon Dioxide) for Quartz. Jasper and Agate are cryptocrystalline varieties of Quartz.
Mineral/Semiprecious Gemstone (variety of Quartz)
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Mineral
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Metamorphic
Banded Gneiss
Gneiss
Metamorphic
Quartzite (river pebble) and Gabbro (crushed rock)
Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)
Metamorphic and Igneous
Hematite
Hematite (Fe2O3)
mineral
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Mineral
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Mineral
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Quartz (SiO₂)
Mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst (Geode Fragment)
Silicon Dioxide (SiO2 with iron impurities)
mineral
Calcite (Yellow/Orange variety - sometimes called Honey Calcite)
Calcite
Mineral
Nephrite Jade
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral
Marble
Metamorphosed Limestone/Dolomite
metamorphic
Graphite
Graphite (Carbon, C)
Mineral
River Stone (Chalcedony/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Gneiss (likely)
Gneiss
Metamorphic
Banded Gneiss
Gneiss (pronounced "nice")
metamorphic
Magnetite
Magnetite (Fe3O4)
Mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Mineral
Quartz
Silicon dioxide (SiO2)
Mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Milky Quartz with Iron Inclusions
Quartz (Silicon Dioxide, SiO2)
mineral
Orange Quartz with Hematite inclusions
Quartz (SiO2) with Hematite (Fe2O3) inclusions
Mineral
Moonstone (bead form)
Potassium Aluminum Silicate (KAlSi3O8) - a variety of Orthoclase Feldspar
Mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Mineral