Mineral And Metamorphic Rock

Granitic Gneiss Pebble

Gneiss (felsic metamorphic rock)

Quartz Vein in Host Rock

Quartz (SiO2) in Mafic or Sedimentary Matrix

Milky quartz (quartz fragment)

Quartz, silicon dioxide (SiO₂)

Milky quartz (likely iron-stained quartz)

Quartz — silicon dioxide (SiO₂)

Weathered mica-rich metamorphic rock, likely schist

Mica schist, probably muscovite–biotite schist with quartz and feldspar

Aquamarine

Beryl (Be3Al2Si6O18)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Tumbled quartz pebbles

Quartz (silicon dioxide, SiO₂), commonly milky or translucent quartz

Small dark mineral/rock fragment

Indeterminate; possibly biotite-rich schist, graphite, or metallic sulfide

Feldspar (Plagioclase / Orthoclase)

KAlSi3O8 / CaAl2Si2O8 - NaAlSi3O8

Polished magnetite-rich ironstone (possible magnetite pebble)

Magnetite, Fe₃O₄; possibly magnetite-bearing basalt or ironstone

Gneiss

Metamorphic Rock (Gneissic texture)

Gneiss (specifically a weathered or stream-worn specimen)

Gneiss (Foliated Metamorphic Rock)

Gneiss

Gneiss (High-grade metamorphic rock)

Foliated metamorphic rock, likely biotite gneiss or schist

Biotite-rich gneiss/schist; chiefly quartz, feldspar, and biotite mica

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Schist

Crystalline Metamorphic Rock (Schistose)

Smoky quartz fragment

Quartz, silicon dioxide (SiO₂), smoky variety

Quartz crystal

Quartz (silicon dioxide, SiO₂), likely a natural or lightly damaged crystal

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Mixed polished rock/mineral specimens

Indeterminate from image; likely quartz-bearing material with iron-oxide staining and possibly mica-rich schist

Garnet Schist

Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)

Foliated metamorphic rock, likely gneiss or mica schist

Quartz–feldspar–mica metamorphic rock; exact identification is uncertain from the photograph

Lapis Lazuli

(Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2 (Complex silicate rock)

Black tourmaline (schorl), likely in a crystal aggregate

Schorl, NaFe3Al6(BO3)3Si6O18(OH)4

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss (a type of metamorphic rock)

Milky quartz specimen

Quartz (silicon dioxide, SiO₂), likely massive milky quartz with possible iron-oxide staining and minor feldspar or mica

Greenstone (or Greywacke/Metasediment Pebble)

Metamorphosed Mafic Rock / Chlorite Schist

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Schist

Mica Schist (contains muscovite/biotite and quartz)

Quartz with Mica

Silicon Dioxide (SiO2) with Mica group inclusions

Serpentinite

Serpentinite (complex silicate minerals including lizardite, chrysotile, and antigorite: (Mg,Fe)3Si2O5(OH)4)

Epidote

Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz Vein in Sedimentary Matrix

Silicon Dioxide (SiO2) with host rock

Unidentified gray-green rock specimen

Possibly banded gneiss or another foliated metamorphic rock; identification is uncertain from the image

Iron-stained milky quartz vein

Quartz (SiO₂), with iron-oxide/hydroxide staining and minor dark inclusions

Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled quartz (likely milky or iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Gabbroic rock, possibly hornblende gabbro

Gabbro; coarse-grained mafic silicate rock dominated by plagioclase and pyroxene, with possible hornblende and magnetite