Sedimentary Or Metamorphic (Low Grade)

Unakite (likely)

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

Veined marble or calcitic limestone

Calcite-dominant carbonate rock (CaCO₃), likely marble

Dark metamorphic rock, likely slate or phyllite

Fine-grained foliated metamorphic rock; commonly dominated by quartz, mica, and chlorite

Polished banded stone, likely tiger’s-eye

Tiger’s-eye quartz (fibrous chalcedony/quartz, SiO₂), possibly iron-rich quartzite

Greenstone (Chert)

Microcrystalline Silica (SiO2) with chlorite/epidote inclusions

Soapstone (steatite), possibly talc-rich schist

Steatite; predominantly talc, Mg₃Si₄O₁₀(OH)₂, with possible chlorite, mica, and carbonates

Engraved polished dark stone (likely slate or basalt)

Probable fine-grained slate (microcrystalline phyllosilicates), possibly basalt; exact identification requires testing

Greenstone Celt (Polished Stone Axe)

Metamorphosed mafic rock (often Basalt or Diabase)

Anthracite Coal

Anthracite

Epidote with Quartz and Feldspar

Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)

Limonite Concretion

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

Tumbled ruby or ruby-bearing corundum

Corundum (Al₂O₃), red variety colored mainly by chromium

Ironstone Concretion

Ironstone (Siderite/Limonite/Goethite)

Conglomerate

Conglomerate Rock

Ironstone Nodules in Chalk/Limestone

Limonite/Goethite concretions (FeO(OH)·nH2O) in Calcium Carbonate matrix (CaCO3)

Ironstone Concretion

Ferruginous Sandstone / Siderite Concretion

Ironstone Concretion (Limonite/Goethite)

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Limonite Concretion

Limonite (FeO(OH)·nH2O)

Ironstone Concretion / Limonite Specimen

Goethite and Limonite (Hydrous Iron Oxides)

Jadeite

NaAl(Si2O6)

Sapphire (Blue/Violet Rough)

Corundum (Al2O3)

Hematitic Sandstone

Sandstone with Hematite inclusions (SiO2 + Fe2O3)

Anthracite Coal

Anthracite

Ironstone (Limonite/Hematite concretion)

Ferruginous Siltstone / Goethite (FeO(OH))

Conglomerate

Conglomerate rock

Tumbled milky quartz

Quartz (SiO₂), microcrystalline or massive variety

Serpentinite (likely)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, commonly with magnetite and minor carbonates

Quartz / Quartzite

Silicon Dioxide (SiO2)

Tumbled greenstone, likely serpentine or altered basalt

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; possibly chlorite/epidote-bearing mafic rock

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Prehnite

Calcium aluminum silicate hydroxide, Ca2Al2Si3O10(OH)2

Rounded, striated pebble—likely slate or fine-grained metamorphic rock

Slate/phyllite; predominantly quartz, mica, and clay-derived minerals

Possible shale or slate fragment

Fine-grained clay-rich rock; possibly slate (low-grade metamorphosed shale)

Tumbled ruby-bearing corundum

Corundum (Al₂O₃), likely ruby variety

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite Ore

Iron Sulfide (FeS2)

Fine-grained dark metamorphic rock, likely slate or phyllite

Slate/phyllite, composed mainly of mica-group minerals, quartz, and clay-derived minerals

Conglomerate

Conglomerate (clastic sedimentary rock)

Tumbled quartz-rich pebble, likely jasper or chert

Microcrystalline quartz (SiO₂), possibly iron-stained jasper

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Jadeite Jade

Jadeite (NaAlSi2O6)