Metamorphic Rock

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

Weathered fossiliferous limestone, likely coral or shell fragment

Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image

Fossil shell fragment, likely bivalve or brachiopod

Indeterminate fossilized mollusk/brachiopod; commonly calcite (CaCO₃)

Feldspar-rich granitoid pebble

Likely granite or granodiorite, composed mainly of quartz, feldspar, and mica

Giallo Ornamental Granite

Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)

Quartz (Milky or Smoky Quartz Pebble)

Silicon Dioxide (SiO2)

Likely gray quartzite or quartz-rich metamorphic fragment

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with mica or feldspar

Rounded gray river pebble, likely basalt or fine-grained volcanic rock

Probable basalt (fine-grained plagioclase–pyroxene rock); exact identification requires testing

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite River Pebble

Quartzite (primarily Silicon Dioxide, SiO2)

Schist

Mica Schist (contains muscovite/biotite and quartz)

Likely hornblende amphibolite fragment

Amphibolite, chiefly hornblende and plagioclase feldspar

Polished brown river pebble

Likely quartzite or weathered metabasalt; exact identification requires hardness and streak tests

Mica Schist

Mica Schist (Main mineral constituents: Muscovite/Biotite, Quartz, Feldspar)

Veined Pebble (likely a Quartz-Veined Pebble)

Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)

Weathered quartz-bearing rock, possibly porphyritic rhyolite

Likely altered rhyolite or dacite containing quartz and feldspar; exact identification requires testing

Fossil-bearing fine-grained sedimentary rock

Likely fossiliferous mudstone or shale; visible feature may be a plant fragment, trace fossil, or mineral vein

Weathered mica-rich rock fragment

Likely mica schist or phyllite; identification is uncertain from the image alone

Fossil shell fragment, likely bivalve or gastropod

Fossilized calcium-carbonate shell; likely aragonite/calcite replaced by calcite

Possible weathered basalt or iron-rich slag

Basalt, tentatively; composition likely plagioclase and pyroxene with possible magnetite

Fossilized bone fragment (probable mammalian tooth or bone)

Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite

Weathered quartz-rich rock, likely granite or quartzite

Indeterminate; probable quartz–feldspar aggregate, possibly granitic gneiss

Dragon Blood Jasper (Dragon Stone)

Epidote-Piemontite/Quartzite Rock

Gneiss

High-grade regional metamorphic rock (Foliated)

Granite

Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Garnet-Mica Schist

Garnetiferous Porphyroblastic Schist

Greenstone (likely serpentinite)

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with chlorite or magnetite

Quartzite (Engineered Stone)

Silicon Dioxide (SiO2) based synthetic composite

Quartz Vein in Matrix (Gneiss/Schist)

Silicon Dioxide (SiO2) in Metamorphic Rock Matrix

Mica Schist with Vein

Mica Schist

Polished operculum (“Shiva eye” shell)

Calcium-carbonate shell operculum, commonly from a turban snail (family Turbinidae); not a mineral specimen

Zebra Jasper (with Chlorite/Epidote)

Silicon Dioxide (SiO2) with inclusions

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Uncertain pale granitoid or weathered feldspathic rock

Likely granite or granodiorite; chiefly quartz, feldspar, and minor mica, but the photograph is insufficient for precise identification.

Schist

Mica Schist (Medium-grade Metamorphic Rock)

Quartzite (River Pebble)

Quartzite (composed primarily of Silica, SiO2)

Milky quartz with iron-oxide staining

Quartz (SiO₂), likely with goethite/limonite coatings

Fuchsite Gneiss or Schist

Muscovite (variety Fuchsite) within Metamorphic Host Rock

Mica Schist

Mica Schist (Quartz-Mica Metamorphic Rock)

Quartz-bearing dark igneous rock, likely gabbro or basalt

Gabbro/basalt dominated by plagioclase and pyroxene, with minor quartz or calcite

Weathered sandstone fragment

Quartz-rich sandstone, likely iron-oxide-stained litharenite

Pyrite in Slate

Iron Sulfide (FeS2) in Slate host matrix