Metamorphic Rock

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite)

Gneiss

Gneiss (a rock type, not a specific mineral with a formula)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Banded Iron Formation

Banded Iron Formation (BIF)

Serpentine

Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)

Banded Gneiss (Variety of Gneiss)

Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)

Rounded gray pebble, likely quartz-rich metamorphic rock

Probable quartzite or fine-grained gneiss; mainly SiO₂ quartz with possible feldspar and mica

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Soapstone

Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)

Quartzite

Quartzite

Gneiss

Gneiss (pronounced 'nice')

Marble

Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.

Banded Gneiss

Gneiss (pronounced "nice")

Greisen (Quartz-Muscovite-Turretine Rock)

Greisen

Serpentine

Serpentinite (rock) containing serpentine minerals (e.g., Antigorite, Lizardite, Chrysotile)

Schist

Mica Schist

Serpentinite

Serpentinite (composed primarily of serpentine-group minerals like antigorite, chrysotile, and lizardite; chemical formula varies but generally Mg3Si2O5(OH)4)

Bloodstone

Heliotrope (a variety of Chalcedony, SiO₂ with inclusions)

Weathered quartz-bearing metamorphic rock, likely gneiss or schist

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

Calcite (likely a tumbled specimen)

Calcite (CaCO 3 )

Likely weathered gneiss

Foliated metamorphic rock, commonly quartz–feldspar–mica gneiss

Wishing Stone with Quartz Veins

Quartzite or Quartz-veined Metamorphic Rock (composed mainly of SiO2)

Ruby in Zoisite

Anyolite (composite of Corundum and Zoisite)

Granitoid Gneiss with Feldspar Vein

Gneiss (High-grade Metamorphic Rock) with Potassium Feldspar (KAlSi3O8)

Biotite-rich gneiss (possibly mica schist)

Quartz–feldspar–biotite gneiss; mica-rich metamorphic rock

Mica Schist

Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)

Weathered gray-green pebble

Indeterminate; possibly altered basalt, serpentinite, or a greenish metamorphic rock

Slate

Foliated Metamorphic Rock (composed mainly of clay minerals or micas)

Dalmatian Stone and Lapis Lazuli

Dalmatian Stone (peralkaline rock) with Lapis Lazuli (metamorphic rock)

Tumbled dark pebble

Indeterminate; likely basalt or fine-grained dark metamorphic rock

Rounded river pebble (likely weathered granite or metamorphic rock)

Indeterminate; possible granitic or quartz-rich lithology

Likely schist, possibly serpentinite

Mica schist; potential chlorite–serpentine-rich metamorphic rock

Coarse-grained mica-bearing metamorphic rock, likely schist

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

Rounded metamorphic pebble, likely quartzite or gneiss

Quartz-rich metamorphic rock; possibly foliated quartzite or gneiss

Gneiss (specifically Biotite Gneiss)

Gneiss (high-grade metamorphic rock primarily composed of Silicates)

Tumbled greenstone (likely serpentine or chlorite-rich metamorphic rock)

Serpentinite, approximately Mg₃Si₂O₅(OH)₄, or chlorite-rich greenstone

Black tourmaline-bearing pegmatite or schorl-rich metamorphic rock

Schorl tourmaline, NaFe3Al6(BO3)3Si6O18(OH)4, with quartz/feldspar and iron-oxide matrix

Granite Gneiss

Metamorphic Rock (Quartz, Potassium Feldspar, Plagioclase, Biotite/Amphibole)

Weathered quartz-bearing metamorphic rock, likely gneiss or quartzite

Quartz-rich gneiss/quartzite with feldspar, mica, and iron-oxide alteration

Weathered greenstone (likely serpentinite or chlorite-rich metamorphic rock)

Serpentinite/chlorite schist; commonly dominated by serpentine-group minerals, Mg-rich chlorite, talc, and magnetite

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

Banded Gneiss

Gneiss (Metamorphic rock predominantly containing quartz, feldspar, and mica)