Mineral And Metamorphic Rock

Small dark mineral or rock fragment

Undetermined; possibly a dark mafic mineral such as biotite or magnetite

Likely quartz-rich rock or mineral fragment

Quartz (SiO₂), possibly in a pegmatitic or granitic matrix

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Rounded quartz-rich pebble

Likely milky quartz or quartzite; SiO₂

Garnet Amphibolite (or Garnet Gneiss)

Garnet amphibolite / Garnet-bearing metamorphic rock

Rounded quartz pebble

Quartz (SiO₂), possibly milky or smoky quartz

Pyrite

Iron Sulfide (FeS2)

Quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a weathered host rock

Quartzite with Feldspar and Mica (Granitic Gneiss Pebble)

Metamorphic Rock / Quartzite / Granitic Gneiss

Likely milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered metamorphic rock, likely schist or phyllite

Quartz–mica schist/phyllite (exact identification requires a fresh surface and tests)

Hematite

Iron Oxide (Fe2O3)

Quartz-rich rock fragment, possibly milky quartz

Quartz (SiO₂), likely a small vein-quartz or quartz-bearing rock fragment

Educational Geologic Collection

Mixed Mineral and Rock Collection (Various compositions)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Green Slate or Metamorphic Rock with Moss/Lichen

Metamorphic rock / Phyllite or Slate variant

Quartz-rich gravel fragment

Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Milky quartz

Quartz (silicon dioxide, SiO₂)

Amphibolite

Amphibolite

Weathered foliated metamorphic rock, likely schist or gneiss

Mica schist to gneiss; commonly quartz + feldspar + biotite/muscovite

Dyed Agate / Quartz

Silicon Dioxide (SiO2) with artificial dye

Quartz-rich rock fragment

Likely milky quartz (SiO₂), possibly a pale quartzite fragment

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂); if quartzite, recrystallized quartz sandstone

Greenschist (or Serpentinite) with Quartz-Feldspar Vein

Metabasalt / Greenschist Facies Rock

Tumbled quartz-rich pebble, likely milky quartz with iron-oxide staining

Quartz (SiO₂), possibly with hematite/goethite inclusions or surface coating

Polished dark river pebble, likely serpentinite or altered ultramafic rock

Serpentinite (predominantly serpentine-group minerals; identification is provisional)

Yellow chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (tentative; possibly iron-stained chalcedony)

Epidote

Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))

Granite-like gneiss

Foliated granitic gneiss, composed mainly of quartz, feldspar, and mica

Clear quartz crystal (likely quartz point or polished quartz)

Quartz, silicon dioxide (SiO₂)

Milky quartz

Quartz (SiO₂)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Biotite-bearing metamorphic rock, likely gneiss or schist

Mica-rich quartz–feldspar gneiss/schist; exact identification requires testing

Weathered metamorphic rock, likely schist or gneiss

Quartz–feldspar–mica metamorphic rock; exact identification requires testing

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Tumbled quartz pebble

Quartz (silicon dioxide, SiO₂)

Quartzite with Mica Matrix

Metamorphic Quartz-Mica Schist/Quartzite

Beaded gemstone bracelet, likely lapis lazuli and pale quartz/agate

Lapis lazuli: lazurite-rich rock, chiefly (Na,Ca)₈(AlSiO₄)₆(S,SO)₂; pale beads are uncertain

Raw quartz specimen

Quartz (silicon dioxide, SiO₂), likely milky quartz