Metamorphic Or Sedimentary Depending On Local Grade

Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Gneiss

Gneiss (Foliated Metamorphic Rock)

Quartz (specifically a water-worn river pebble)

Silicon Dioxide (SiO2)

Likely slate fragment

Slate; fine-grained foliated metamorphic rock, commonly quartz–mica–chlorite rich

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Quartz (Milky or Yellow/Citrine Quartz)

Silicon Dioxide (SiO2)

Fuchsite in Quartz (or Emerald in Fuchsite / Verdite)

Chromian Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Quartz Matrix

Greenstone or Epidote-rich rock

Epidote or Chlorite schist/greenstone

Gray slate

Slate; fine-grained foliated metamorphic rock composed mainly of mica and quartz

Gneiss (with iron staining)

Gneiss

Slate

Slate (Foliated Metamorphic Rock)

Anthracite Coal

Anthracite

Garnet amphibolite / Metamorphic Rock

Garnet Amphibolite (Hornblende - Almandine schist/gneiss)

Greenstone / Greenschist

Greenschist (composed of Chlorite, Epidote, Actinolite)

Schist

Schist

Weathered gray metamorphic rock, likely slate or phyllite

Foliated metapelite; composition commonly quartz, mica, and chlorite

Likely slate or fine-grained metamorphic rock

Slate; predominantly microcrystalline quartz, mica, and clay minerals

Blue Kyanite

Kyanite (Al2SiO5)

Whetstone

Novaculite

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Feldspathic Granite (likely Syenite or Granite Pegmatite)

Phaneritic Acidic Igneous Rock (KAlSi3O8 dominant with SiO2)

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Gneiss

Banded orthogneiss or paragneiss, typically quartz–feldspar–mica bearing

Foliated metamorphic rock, likely slate or phyllite

Fine-grained metapelite; commonly quartz–mica–chlorite with possible graphite

Schist

Mica Schist

Blue Calcite

Calcium Carbonate (CaCO3)

French Bulldog (Blue Variety)

Canis lupus familiaris

Sapphirine in Matrix

Sapphirine (Mg,Al)8(Al,Si)6O20

Weathered foliated metamorphic rock, likely schist or phyllite

Micaceous quartz–feldspar schist/phyllite; exact identification requires microscopy or testing

Mica Schist with Garnet inclusions

Mica Schist (primarily Muscovite and Biotite - KAl2(AlSi3O10)(OH)2)

Water-worn green pebble

Likely altered basalt or greenstone; precise identification requires testing

Larimar

Pectolite (NaCa2Si3O8(OH))

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Quartz with inclusions

SiO2

Mixed river-worn rock collection

Uncertain; likely quartzite, sandstone, basalt, and weathered granite or gneiss

Amethyst Beads

Quartz (Silicon Dioxide, SiO2 with iron impurities)

Dark gray metamorphic pebble, likely slate or phyllite

Slate/phyllite; chiefly fine-grained quartz, mica, and clay-derived minerals

Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression)

Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)

Likely slate or fine-grained metamorphic rock

Slate/phyllite; predominantly fine-grained mica, chlorite, and quartz

Quartz (Bull Quartz)

Silicon Dioxide (SiO2)

Basalt

Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)