Metamorphic (Likely Gneiss Or Schist Based On Texture)

Schorl (Black Tourmaline)

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4

Schorl (Black Tourmaline)

NaFe3Al6(BO3)3Si6O18(OH)4 (Complex Borosilicate)

Lepidolite (likely)

K(Li,Al)3(Al,Si)4O10(F,OH)2 (Phyllosilicate mineral, part of the mica group)

Fine-grained dark igneous rock, likely basalt

Basalt; predominantly plagioclase feldspar and pyroxene, commonly with minor olivine and iron-titanium oxides

Dark gray weathered pebble, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Ruby

Corundum (Aluminum Oxide with Chromium traces), Al2O3:Cr

Raw Emerald

Beryl (Be3Al2(SiO3)6) with Cr/V impurities

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

Quartzite with Quartz Vein

Metamorphosed Quartz-rich Sandstone (SiO2)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals Mg₃Si₂O₅(OH)₄, with magnetite, olivine, and pyroxene remnants

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Weathered basalt (likely vesicular basalt)

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Quartz with Schist Matrix

Crystalline Silicon Dioxide (SiO2) in micaceous schist

Wishing Stone (Gneiss or Basalt with Quartz Vein)

Gneiss or Metabasalt (with a Quartz or Calcite intrusion)

Milky Quartz in Gneiss

Quartzite / Foliated Gneiss containing SiO2

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Ferruginous Quartz (Iron-stained Quartzite)

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Quartzite

Quartzite (SiO2)

Dark rounded pebble, likely basalt

Basalt (fine-grained mafic volcanic rock; commonly plagioclase, pyroxene, and olivine)

Iron-rich quartzite or silicified ironstone

Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite and possibly hematite

Serpentine

Serpentinite (complex of Mg, Fe, Ni, Al, Zn, Mn)Si2O5(OH)4

Tumbled jasper, likely red/brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica assemblage

River Rock (Quartzite)

Quartzite (SiO2)

Eclogite

Eclogite (Omphacite + Almandine-Pyrope Garnet)

Green aventurine quartzite (likely)

Quartz-rich metamorphic rock; predominantly microcrystalline quartz (SiO₂), with possible fuchsite, chlorite, or epidote

Serpentinite (likely polished/tumbled)

Serpentinite; chiefly serpentine-group minerals, commonly antigorite, lizardite, and chrysotile, with magnetite and accessory carbonates

Andesite

Andesite (Intermediate Extrusive Igneous Rock)

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)

Sandstone (with Laminations)

Clastic sedimentary rock (primarily Quartz-based)

Polished limestone or marble slab

Calcite-rich carbonate rock; likely marble (CaCO₃)

River Pebble (likely Quartzite or Basalt)

Quartzite (SiO2 as primary mineral)

Granite

Felsic Plutonic Igneous Rock

Quartzite Pebble

Metamorphic Quartzite (primarily SiO2)

Fuchsite

Cr-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Likely serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, possibly with magnetite, chromite, and brucite

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, olivine, pyroxene, and sulfides

Weathered quartz-rich cobble (likely quartzite or vein quartz)

Quartzite, predominantly SiO₂; possibly weathered vein quartz

Likely quartz-rich pebble (possibly weathered quartzite)

Quartzite; predominantly SiO₂ (identification tentative from photograph)