Sedimentary Or Metamorphic (Low Grade)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Biotite mica schist (probable)

Mica schist, dominated by biotite; approximate mica formula K(Mg,Fe)₃AlSi₃O₁₀(OH)₂

Epidote in Quartz

Epidote (Ca2(Al,Fe)3(SiO4)3(OH)) in Milky Quartz (SiO2)

Dark gray metamorphic rock, likely slate or phyllite

Slate/phyllite; commonly quartz–mica–chlorite aggregate

Limonite

FeO(OH)•nH2O

Ruby (Corundum)

Aluminum oxide (Al2O3) with Chromium traces

Ruby

Corundum (Al2O3 with Chromium traces)

Green Schist

Greenschist (composed of chlorite, epidote, and actinolite)

Emerald in Quartz Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

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

Red Jasper

Silicon dioxide (microcrystalline quartz, $SiO_2$)

Jasper with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate (Ca2(Al,Fe)3(SiO4)3(OH))

Green Jasper

Silicon Dioxide (SiO2)

Purple Slate

Foliated slate (Pelitic origin)

Ferruginous Sandstone (Ironstone Conglomerate fragments)

Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)

Greenstone

Metamorphic mafic rock (greenschist facies)

Zoisite with Ruby (Anyolite)

Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)

Conglomerate

Conglomerate (clastic sedimentary rock)

Conglomerate

Conglomerate (clastic sedimentary rock)

Conglomerate

Conglomerate (clastic sedimentary rock)

Conglomerate

Conglomerate rock

Stiped Slate Beach Pebble

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

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Ironstone Concretion (Limonite/Goethite)

Ferruginous Siltstone / Limonite Concretion (FeOO(OH)·nH2O)

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (Iron-rich)

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

Dark gray metamorphic rock fragment, likely slate or schist

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

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)

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Ironstone (Limonite/Hematite concretion)

Ferruginous Siltstone / Goethite (FeO(OH))

Ferruginous Sandstone

Arenite with Iron-Oxide cement (Fe2O3 · nH2O)