Mineral And Metamorphic Rock

Gneiss and Igneous Rock Collection

Foliated Metamorphic Rock (Gneiss) / Igneous Rocks

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Tumbled quartz crystal

Quartz (silicon dioxide, SiO₂)

Weathered, iron-stained rock (likely metamorphic)

Indeterminate from photograph; possibly quartz-rich gneiss or schist

Slickenside

Tectonic Fault Scarp Surface

Banded gneiss

Gneiss, commonly quartz–feldspar–mica gneiss

Epidotite (Unakite-related)

Epidote-rich rock

Citrine

Silicon Dioxide (SiO2)

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (SiO₂), potentially quartzite if the grainy texture is rock-wide

Greenschist

Greenschist facies rock

Slate

Slate (foliated metamorphic rock)

Slate

Slate (foliated metamorphic rock)

Gneiss Pebble

Gneiss

Banded gneiss

Foliated gneiss, likely quartz–feldspar–biotite or amphibole gneiss

Weathered mafic metamorphic rock, likely serpentinite or altered basalt

Probably serpentinized ultramafic rock; commonly dominated by serpentine-group minerals, with magnetite and altered pyroxene/olivine

Marble

Metamorphic Limestone (CaCO3)

Yellow Quartz

Silicon Dioxide (SiO2)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Quartzite

Metamorphic rock consisting largely of Quartz (SiO2)

Quartz Pebble (with Feldspar/Mica)

Granitic Quartz / SiO2 with KAlSi3O8

Painted River Rock

Artificially Coated Sedimentary Rock

Blue Agate (Dyed Chalcedony)

Silicon Dioxide (SiO2)

Veined Grey Metamorphic Pebble

Quartzo-feldspathic vein in Metabasalt / Serpentinite / Slate

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Tiger Iron

Tiger Iron (Composition: SiO2, Fe2O3, Fe3O4)

Dark, coarse-grained rock fragment (possibly amphibolite or gabbro)

Uncertain from the photo; likely amphibolite (hornblende-rich metamorphic rock) or a mafic igneous rock such as gabbro

Pyrite in Matrix

Iron Sulfide (FeS2)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Ruby in Zoisite

Anyolite

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz–feldspar–mica metamorphic rock, likely gneiss

Gneiss; composition commonly quartz (SiO₂), feldspars, biotite/hornblende, and minor accessory minerals

Epidote (Unakite component) / Green Quartzite

Ca2(Al,Fe)3(SiO4)3(OH)

Likely serpentinite (serpentine-rich rock)

Serpentinite, composed mainly of serpentine-group minerals (e.g., antigorite, lizardite, or chrysotile)

Serpentine

Antigorite/Lizardite (Mg, Fe)3Si2O5(OH)4

Quartzite Pebble

Metamorphic Rock (rich in SiO2)

Granite

Felsic intrusive igneous rock

Foliated metamorphic rock, likely gneiss or schist

Biotite–quartz–feldspar gneiss/schist; exact identification requires mineral and texture testing

Tiny amber-colored crystal fragment

Indeterminate; possibly quartz, feldspar, mica, or a sulfide mineral

Quartz with Mica/Schist inclusion

Silicon Dioxide (SiO2) with Phyllosilicates

Gneiss (probable banded metamorphic rock)

Banded gneiss; typically quartz–feldspar–mica assemblage

Polished pyrite specimen

Pyrite (FeS₂), cubic iron disulfide