Metamorphic (Low Grade)

Greenschist

Chlorite schist

Phyllite

Phyllite

Greenstone

Metamorphic Rock (Greenschist facies)

Serpentine

Serpentine-group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Corundum (Ruby/Sapphire crystal)

Al2O3 (Aluminum Oxide)

Tiger's Eye

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

Graphitic schist (likely carbonaceous slate)

Graphite-bearing pelitic schist; mainly quartz, mica, feldspar, and graphite

Tumbled lapis lazuli

Lazurite-bearing calcite rock; lazurite approximately Na₃Ca(Si₃Al₃)O₁₂S

Green Jadeite

Jadeite, NaAl(Si2O6)

Greenschist

Greenschist (Chlorite-actinolite schist)

Schist

Metamorphic Schist

Greenstone (Greywacke or Nephrite Jade variant)

Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)

Pink-and-white quartz-rich pebble

Quartz (SiO₂), likely massive quartz with iron-oxide staining and possible feldspar inclusions

Fine-grained, foliated rock (possibly slate or phyllite)

Undetermined; likely slate or phyllite, composed mainly of quartz, mica, and chlorite

Red-and-black slate

Slate, a fine-grained metamorphic rock composed mainly of clay-derived mica minerals and quartz

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Likely blue-gray slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

Likely serpentine or weathered greenstone pebble

Serpentine-group minerals, chiefly antigorite/lizardite; possibly chlorite–actinolite greenstone

Rounded blue-gray stone, likely slate or fine-grained metamorphic rock

Probable slate/phyllite; composition mainly quartz, mica, and feldspar

Pale-green schist fragment

Chlorite–sericite schist, possibly containing epidote or actinolite

Anthracite

Anthracite coal

Foliated metamorphic rock, likely slate or phyllite

Fine-grained metapelite; commonly quartz–mica–chlorite with possible graphite

Weathered gray metamorphic rock, likely slate or phyllite

Fine-grained foliated metamorphic rock; commonly quartz–mica–chlorite, possibly chlorite phyllite

Greenstone / Epidosite

Metamorphosed Mafic Igneous Rock (Epidote-Chlorite group)

Schist (Greenschist / Mica Schist)

Foliated Metamorphic Rock (rich in chlorite, muscovite, and quartz)

Epidote (Unakite component) / Green Quartzite

Ca2(Al,Fe)3(SiO4)3(OH)

Greenstone

Metabasalt / Chlorite schist

Greenstone Pebble

Metabasalt / Greenstone

Greenstone

Metabasalt

Greenstone (Diabase or Metabasalt)

Metamorphosed Mafic Igneous Rock

Garnet Schist

Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)

Milky quartz vein fragment

Quartz (SiO₂), likely massive or vein quartz with minor iron-oxide/clay inclusions

Tumbled yellow-green stone, likely serpentine or nephrite jade

Serpentine-group mineral, commonly antigorite/lizardite; possible nephrite, a tremolite–actinolite amphibole aggregate

Green Calcite

Calcium Carbonate (CaCO3)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Likely tumbled greenstone (identity uncertain)

Greenstone: metamorphosed mafic volcanic rock, commonly composed of chlorite, actinolite, and epidote

Banded gray stone, likely slate or fine-grained metamorphic rock

Probably slate or phyllite; composition commonly mica, quartz, and clay-derived minerals

Likely slate fragment

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

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Weathered schist or phyllite

Mica schist/phyllite; quartz–mica-rich foliated metamorphic rock

Likely slate or fine-grained metamorphic rock

Slate/phyllite; predominantly fine-grained mica, chlorite, and quartz

Greenschist

Greenschist (Chlorite Schist)