Metamorphic Or Mineral

Gneiss

Gneissic Metamorphic Rock

Pink Quartz

Silicon Dioxide (SiO2)

Gneiss (Metamorphosed Granitic Rock)

Gneiss (composed mainly of quartz, feldspar, biotite, and/or hornblende)

Fuchsite Gneiss or Schist

Muscovite (variety Fuchsite) within Metamorphic Host Rock

Clear Quartz (Faceted)

Silicon dioxide (SiO2)

Epidote and Quartz in Basalt

Epidote [Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)] in Metabasalt

Tumbled green aventurine

Quartz (SiO₂) with fuchsite or other green mica inclusions

Tumbled green aventurine (probable)

Quartzite composed chiefly of quartz (SiO₂), with green fuchsite or other mica inclusions

Magnetite-rich ironstone (probable magnetite ore)

Magnetite, Fe₃O₄, likely in a fine-grained ironstone matrix

Pyrite

Iron Pyrite (FeS2)

Pyrite (on the right) and Magnetite or Hematite (on the left)

Iron Sulfide (FeS2) and Iron Oxide (Fe3O4 or Fe2O3)

Rhodonite

Manganese Silicate (Mn, Fe, Mg, Ca)SiO3

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Yellow Calcite

Calcium Carbonate (CaCO3)

Calcite

Calcium Carbonate (CaCO3)

Pyrite

Iron Disulfide (FeS2)

Optical Calcite

Calcium Carbonate (CaCO3)

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Quartz

Silicon Dioxide (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Banded gneiss

Gneiss, commonly quartz–feldspar–biotite gneiss

Tumbled banded gneiss or amphibolite

Banded metamorphic rock, likely quartz–feldspar–biotite gneiss with amphibole

Pale green stone, possibly serpentine

Serpentinite (dominantly serpentine-group minerals; visual identification is uncertain)

Black tourmaline (likely schorl)

Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Tumbled quartz-rich pebble

Quartz (SiO₂), likely with iron-oxide staining and minor inclusions

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions) - SiO2

Greenschist

Greenschist (Chlorite-actinolite schist)

Banded gneiss

Foliated gneiss, likely quartz–feldspar–mica gneiss

Banded metamorphic rock, likely gneiss or schist

Foliated quartz–feldspar–mica rock; exact identification requires a closer view or mineral testing

Dark metamorphic rock, likely schist or gneiss

Mica schist/gneiss; commonly quartz + feldspar + biotite, with possible amphibole

Foliated metamorphic rock, likely mica schist

Mica schist, mainly quartz–feldspar–mica assemblage

Greenstone

Metabasalt / Chlorite-actinolite-epidote schist

Banded gneiss (likely orthogneiss or paragneiss)

Gneiss; composition commonly quartz + feldspar + mica, with possible amphibole/biotite

Quartz fragment

Silicon Dioxide (SiO2)

Vein-bearing metamorphic rock, likely gneiss or schist

Banded silicate rock; likely quartz–feldspar–mica gneiss with a quartz vein

Blue Quartz

Silicon Dioxide (SiO2) with inclusions

Prehnite

Ca2Al(AlSi3O10)(OH)2

Schist

Mica Schist (Metamorphic rock)

Ruby (Raw Corundum)

Al2O3 (Aluminum Oxide)

Gneiss with Quartz Veining

Gneiss (High-grade Metamorphic Rock)