Metamorphic Rock

Green Aventurine

Silicon Dioxide (SiO2) with inclusions

Biotite Mica Schist

Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2

Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Quartzite (Pink / Peach)

SiO2 (Metamorphosed Quartz Sandstone)

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Gneiss

Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)

Light-colored pebble, likely quartzite or weathered limestone

Indeterminate from image; possible quartzite (microcrystalline SiO₂)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Tiger's Eye (Oeil de Tigre)

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Quartzite

Quartzite (SiO2)

Lapis Lazuli

Lapis Lazuli (Complex rock primarily composed of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Lapis Lazuli (polished cabochon)

Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)

Amphibolite with Hornblende

Amphibole-rich Metamorphic Rock (Ca2(Mg,Fe)5Si8O22(OH)2)

Rounded gray river pebble, likely quartz-rich metamorphic rock

Probable quartzite or quartz-rich schist; exact identification is uncertain from the photograph

Lapis Lazuli (Tumbled Stone)

Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (Lazulite-rich Metamorphic Rock)

Yellow Quartzite

Quartzite (SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Quartz Crystal Cluster on Matrix

Silicon Dioxide (SiO2)

Waterworn greenstone pebble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

Quartz with Mica / Chlorite Inclusion

Silicon Dioxide (SiO2) with Phyllosilicate minerals

Rounded quartz-veined pebble

Likely quartz-veined metamorphic rock; exact host rock is indeterminate from the image

Rounded greenstone pebble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Quartzite

Quartzite (principally SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Quartz (Smoky/Granular variety)

Silicon Dioxide (SiO2)

Likely tumbled lepidolite-bearing mica schist

Lepidolite-rich mica schist; chiefly lepidolite/muscovite mica, quartz, and possibly feldspar

Rounded quartz-rich pebble, possibly milky quartz

Quartz (SiO₂), provisional identification

Rose Quartz

Quartz (Silicon Dioxide, SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Tiger's Eye (Inlaid in a band)

SiO2 (Silicon Dioxide with Crocidolite inclusions)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Quartz Crystal

Silicon Dioxide (SiO2)

Gray slate

Slate; fine-grained foliated metamorphic rock composed mainly of mica and quartz

Slate

Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)

Serpentine Schist with Quartz Vein

Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).

Rounded quartz-rich pebble

Likely granitoid-derived quartz–feldspar rock; exact identification uncertain from image