Metamorphic (Low Grade)

Weathered greenstone (metamorphosed mafic rock)

Chlorite- and epidote-bearing metabasalt; exact identification requires examination

Dragon Blood Jasper (Dragon Stone)

Epidote-Piemontite/Quartzite Rock

Likely serpentine or weathered greenstone pebble

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

Greenstone pebble

Likely chlorite- and/or actinolite-bearing metamorphic rock; exact composition cannot be determined from the image.

Likely blue-gray slate

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

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

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Garnet Schist

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

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

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

Greenstone (likely greenschist)

Chlorite–actinolite–epidote-rich metabasalt; mineral proportions cannot be confirmed from the photo

Likely greenstone (metamorphosed mafic rock)

Greenstone; commonly chlorite–actinolite–epidote–albite assemblage

Fine-grained metamorphic rock, likely slate or phyllite

Slate/phyllite; composition commonly quartz, mica, and chlorite

Water-worn greenstone pebble

Greenstone (metamorphosed mafic volcanic rock; commonly chlorite–actinolite–epidote-bearing metabasalt)

Weathered greenish-gray rock fragment, likely serpentinite or chlorite-rich metamorphic rock

Tentative identification: serpentinite (serpentine-group minerals) or chlorite-bearing metamorphic rock; image alone cannot distinguish them reliably

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)

Likely basaltic or mafic metamorphic rock

Fine-grained mafic rock, probably basalt or altered basalt; composition mainly plagioclase and pyroxene, possibly chlorite/epidote

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Weathered dark shale or slate-like rock

Fine-grained argillaceous rock; exact identification requires examination of a fresh surface

Stream-worn greenstone (likely serpentinite or altered basalt)

Serpentinite, chiefly serpentine-group minerals; possibly chlorite–actinolite greenstone

Emerald

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

Green Calcite

Calcium Carbonate (CaCO3)

Milky quartz vein fragment

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

Slate

Slate (Foliated Metamorphic Rock)

Greenstone (Metabalt)

Chlorite-actinolite schist (Greenstone)

Black Beach Pebble (Basalt / Slate)

Basalt / Metamorphic Slate pebble