Metamorphic (Low Grade)

Emerald in Quartz Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Slate or thinly bedded shale

Slate; primarily fine-grained mica/clay minerals and quartz

Iron-rich jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony (SiO₂) colored by hematite/goethite; possibly iron formation

Dark slate or fine-grained metamorphic rock

Slate; chiefly fine-grained phyllosilicates, quartz, and feldspar

Purple Slate

Foliated slate (Pelitic origin)

Greenstone

Metamorphic mafic rock (greenschist facies)

Stiped Slate Beach Pebble

Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)

Schist

Mica Schist

Likely slate fragments

Slate, a fine-grained metamorphic rock composed chiefly of quartz, mica, and chlorite

Rounded greenstone pebble

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

Greenschist

Greenschist (Chlorite-Epidote-Actinolite Schist)

Anthracite Coal

Anthracite (high-rank coal)

Greenstone pebble (likely altered basalt)

Chlorite–actinolite–epidote altered basalt; precise identification requires testing

Greenstone, possibly serpentine or altered basalt

Serpentinite (Mg₃Si₂O₅(OH)₄) or chlorite-epidote altered basalt; identification is uncertain from the image

Weathered greenstone

Metamorphosed mafic rock, commonly chlorite–actinolite schist or altered basalt

Dark gray metamorphic rock fragment, likely slate or schist

Fine-grained foliated silicate rock; composition likely quartz, feldspar, mica, and/or chlorite

Greenstone / Graywacke

Metagraywacke or Chlorite Schist

Pyrite in Slate

Iron Sulfide (FeS2) in Slate host matrix

Tumbled greenstone/chlorite-rich pebble

Likely chlorite-rich greenschist or altered basalt; exact identification requires testing

Polished tiger’s-eye cabochon (probable)

Quartz variety, SiO₂, with fibrous riebeckite/crocidolite-derived inclusions

Lapis Lazuli

Lapis Lazuli (Complex silicate: Na8[Al6Si6O24]Sn)

Banded Slate (Sedimentary Pebble)

Slate (Metamorphosed Shale or Mudstone)

Gossan (Iron Hat)

Goethite-Hematite rich weathered rock (Fe-hydroxides)

Slate

Slate; fine-grained foliated metamorphic rock, commonly derived from shale or mudstone

Raw Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Slate

Slate; fine-grained metamorphosed shale, commonly quartz–illite/chlorite rich

Jadeite (Jade)

Jadeite; NaAlSi2O6

Red Jasper

Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)

Prase quartz with actinolite inclusions

Silicon dioxide (SiO2) with Calcium Magnesium Iron Silicate Hydroxide inclusions

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Sapphire (Blue/Violet Rough)

Corundum (Al2O3)

Jadeite Jade

Jadeite (NaAlSi2O6)

Tumbled ruby or ruby-bearing corundum

Corundum (Al₂O₃), red variety colored mainly by chromium

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Serpentinite

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

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Gray slate

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

Weathered slate or phyllite

Foliated metamorphic rock, commonly quartz–mica–chlorite assemblage

Tumbled tiger’s-eye

Quartz variety with fibrous crocidolite pseudomorphs; SiO₂

Unakite (likely)

Epidote–orthoclase–quartz rock; composition approximately epidote Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH) plus K-feldspar and quartz