Metamorphic Rock

Tiger's Eye

Silicon Dioxide with Crocidolite (SiO2)

Gneiss (Hornblende/Biotite Gneiss)

Foliated Metamorphic Rock (Quartz-Feldspar-Amphibole/Mica matrix)

Slate

Low-grade Metamorphic Rock (composed of quartz, illite, chlorite)

Slate

Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)

Weathered sulfide-bearing metamorphic rock (probable pyrite schist)

Quartz–mica schist with iron sulfides, chiefly pyrite (FeS₂), possibly chalcopyrite (CuFeS₂)

River Cobble (Gneiss/Migmatite)

Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)

Lapis Lazuli (Low Grade)

Lapis Lazuli (Metamorphic rock containing lazurite, calcite, and pyrite)

Marble

Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)

Mica Schist

Metamorphic rock predominantly composed of muscovite or biotite with quartz and feldspar

Marble

Metamorphic Rock (composed primarily of recrystallized calcite, CaCO3, or dolomite)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

Slate

Foliated Metamorphic Rock (composed mainly of Quartz, Illite, and Chlorite)

Granite Gneiss

High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)

Diamond Drill Core (Greenschist and Quartzite)

Chlorite Schist / Meta-quartzite (Metamorphic Rock Core Sample)

Gneiss

Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Greenschist

Chlorite schist (Metamorphic rock dominated by chlorite, epidote, and actinolite)

Dyed Agate / Quartz

Silicon Dioxide (SiO2) with artificial dye

Green Aventurine

Quartz with fuchsite inclusions (SiO2)

Mixed rock fragments, likely granite and weathered metamorphic rock

Granite (quartz–feldspar–mica aggregate) with probable schist/gneiss fragments

Lapis Lazuli

Lazurite with Calcite and Pyrite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2

Unidentified small mineral fragments

Likely quartz- or feldspar-rich material; species cannot be determined reliably from the image

Aventurine

Aventurine Quartz (SiO2 + Fuschite inclusions)

Quartz–feldspar-bearing metamorphic rock, likely gneiss or migmatite

Band­ed quartzofeldspathic gneiss; chiefly quartz (SiO₂), feldspar, mica, and dark amphibole/biotite

Likely weathered quartz-rich rock fragment

Uncertain; possibly granitic pegmatite or quartz-bearing metamorphic rock

Banded iron formation (likely iron-rich metamorphic rock)

Banded iron formation; hematite–magnetite with chert/jasper (Fe₂O₃/Fe₃O₄ and SiO₂)

Gneiss

Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)

Weathered schist or gneiss fragment

Quartz–feldspar–mica metamorphic rock; likely mica schist or gneiss

Likely weathered gneiss or mica-rich schist

Foliated metamorphic rock, probably quartz–feldspar–biotite gneiss/schist

Weathered quartz-bearing rock, possibly gneiss or quartzite

Indeterminate; likely quartz-rich metamorphic rock containing quartz and feldspar

Aventurine (Green Quartz)

Silicon dioxide with inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Banded Gneiss

Gneiss (Metamorphic rock of variable mineralogy, often quartz-feldspar base)

Lapis Lazuli

Lapis Lazuli (Metamorphic Rock containing Lazurite, Calcite, Pyrite, and Sodalite)

Slate

Foliated Metamorphic Rock (composed primarily of silica and alumina with iron and magnesium)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Lapis Lazuli

Lapis Lazuli (Rock containing Lazurite, Calcite, and Pyrite)

Quartz with Mica/Schist inclusion

Silicon Dioxide (SiO2) with Phyllosilicates

Milky Quartz

Silicon Dioxide (SiO2)

Aventurine

Silicon Dioxide (SiO2) with inclusions

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions