Mineral And Metamorphic Rock

K-Feldspar (Potassium Feldspar)

Orthoclase / Microcline (KAlSi3O8)

Quartz vein fragment

Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions

Quartz

Silicon Dioxide (SiO2)

Weathered, quartz-rich metamorphic rock (likely schist or gneiss)

Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining

River Stone (possibly Gneiss)

Metamorphic Gneiss

Muscovite Mica

Muscovite: KAl2(AlSi3O10)(OH)2

Rhodonite

Rhodonite (MnSiO3)

Quartz-rich metamorphic rock, likely milky quartzite

Quartzite; predominantly quartz (SiO₂), with minor mica, feldspar, and iron-oxide staining

Tumbled Black Tourmaline

Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)

Agate

Silicon Dioxide (SiO2)

Granite Gneiss

Granitic Gneiss

Quartzite with Mica / Gneiss Pebble

Metamorphic Rock (Quartz-Feldspar-Mica aggregate)

Milky quartz

Quartz (silicon dioxide, SiO₂)

River Cobble (Gneiss/Schist mix)

Foliated Metamorphic Rock (Gneissic/Schistose)

Milky quartz vein rock

Quartz (SiO₂), likely in a quartz-rich host rock with minor iron-stained minerals

Milky quartz

Quartz (silicon dioxide, SiO₂)

White marble (likely calcitic marble)

Calcite-rich marble; primarily calcium carbonate, CaCO₃

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Gneiss

Gneiss (High-grade metamorphic rock)

Likely gray-green metamorphic rock fragment

Unidentified fine-grained metamorphic rock; exact identification is not possible from this small image

Chrysocolla on Matrix

Hydrated copper silicates ((Cu,Al)2H2Si2O5(OH)4·nH2O)

Polished pyrite (likely)

Pyrite, FeS₂; possibly a pyrite-rich sulfide specimen

Lapis Lazuli (Low Grade)

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2)

Small rounded stone or mineral fragment

Indeterminate; likely a common quartz- or feldspar-bearing silicate fragment

Leopard jasper (orbicular jasper)

Silicified volcanic rock, chiefly microcrystalline quartz/chalcedony (SiO₂) with feldspar and iron-oxide inclusions

Greenstone

Protolith: Basaltic rock

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Waterworn Pebble / Quartzite

Metamorphic/Sedimentary rock fragment

Greenschist

Greenschist facies metamorphic rock

Dark gray fine-grained stone, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and iron oxides

Greenstone pebble (likely serpentinite)

Serpentinite, composed mainly of serpentine-group minerals

Uncertain dark metamorphic rock, likely schist or slate

Foliated silicate rock; possibly chlorite–mica schist or slate

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2)

Green Aventurine

Quartz with fuchsite inclusions (SiO2)

Unidentified weathered rock fragments

Likely mixed quartz- and feldspar-bearing silicate material; exact identification requires testing

Quartz Veined Rock (Likely Graywacke or Quartzite)

Silicon Dioxide (SiO2) veins in Metasedimentary matrix

Pyrite in Matrix (Fool's Gold)

Iron Disulfide (FeS2)

Banded Metamorphic Rock

Gneiss or Schist

Quartzite with Schist layers

Metamorphosed Quartz-rich Rock (Mixed Schist/Quartzite)

Greenstone / Greenschist

Greenschist facies metamorphic rock

Polished metallic sulfide-bearing pebble

Likely pyrite-bearing slate, schist, or sulfide-rich ore; exact identification requires testing

Agate

Silicon Dioxide (Chalcedony), SiO2