Sedimentary And Metamorphic

Tumbled brown quartzite or jasper

Quartzite (mostly SiO₂), possibly iron-rich jasper (microcrystalline quartz)

Iron-rich quartzite or ironstone fragment

Quartzite dominated by quartz (SiO₂), with iron oxides such as hematite/goethite

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz with Mica Schist Matrix

Quartz (SiO2) in Mica Schist Matrix

Mica Schist with Quartz

Mica Schist (principally Muscovite and Biotite with Quartz veins)

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

Hematite

Iron Oxide (Fe2O3)

Marble (polished)

Recrystallized Calcite (CaCO3)

Quartzite / Iron-stained Chert

Silicon Dioxide (SiO2) with Iron Oxide impurities

White Marble

Recrystallized Calcite (CaCO3)

Almandine Garnet in Matrix

Almandine, Fe3Al2(SiO4)3

Gneiss

Gneiss

Garnet Schist

Almandine Garnet in Schist (X3Al2(SiO4)3)

Pink Garnet (likely Almandine or Rhodolite)

Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)

Garnet-bearing gneiss

Quartz–feldspar–mica gneiss with iron-rich garnet (commonly almandine)

Mica-rich Schist fragment

Mica Schist

Granitic Gneiss

Gneiss (high-grade metamorphic rock)

Marble

Recrystallized Calcite (CaCO3) Rock

Gneiss

Gneiss (foliated metamorphic rock)

Coarse Sand or Fine Gravel

Detrital Sedimentary Fragments (mostly SiO2)

Foliated metamorphic rock, likely biotite schist

Mica schist, chiefly quartz, feldspar, and biotite mica

Gneiss (Metamorphic Pebble)

Gneiss (SiO2-rich metamorphic rock)

Anthracite Coal

Anthracite (Carbon-based sedimentary-metamorphic rock)

Schist

Chlorite/Mica Schist

Gneiss (Metamorphic Rock)

Gneiss (high-grade regional metamorphic rock)

Gneiss (Metamorphic Cobble)

Gneiss (High-grade Regional Metamorphic Rock)

Quartz-rich sandstone or quartzite fragment

Likely quartz arenite; possibly weakly metamorphosed quartzite (mostly SiO₂)

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz with Schist Matrix

Crystalline Silicon Dioxide (SiO2) in micaceous schist

Hard Sandstone (Quartzite)

Quartz-rich Sedimentary Rock (Proto-Quartzite)

Banded gneiss

Gneiss; typically quartz–feldspar–mica assemblage

Quartz

Silicon Dioxide (SiO2)

Blue-gray quartz-bearing metamorphic rock (likely gneiss or schist)

Quartz–feldspar–mica rock; exact identification requires testing

Banded gneiss pebble

Gneiss, chiefly quartz–feldspar–mica with dark biotite/amphibole bands

Quartzite

Quartzite (SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Nephrite Jade

Nephrite

Zebra Rock / Zebra Marble

Banded Limestone-Marble Transition

Gneiss

Gneiss (Foliated Metamorphic Rock)

Schist

Mica Schist (Metamorphic Rock)

Mica Schist

Muscovite Schist (KAl2(AlSi3O10)(OH)2)