Metamorphic (Likely Gneiss Or Schist Based On Texture)

Mixed polished river stones

Likely quartz, quartzite, chert/jasper, and possibly limestone or marble

Tumbled green-and-white stone, likely serpentine

Serpentinite; mainly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnesite or talc

Likely calcite-rich limestone or marble

Calcite (CaCO₃); possibly recrystallized limestone (marble)

Blue Quartz (Dumortierite Quartz / Celestite)

Silicon Dioxide (SiO2) with inclusions

Likely purple quartzite or purple chert

Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing

Coquina (Fossiliferous Limestone)

Coquina (Organic Clastic Limestone)

Sandstone (Muddy/Silty Variety)

Arenite with high silt/clay content (clastic sedimentary rock)

Citrine (likely Heat-Treated Amethyst)

Silicon Dioxide (SiO2)

Polished pink-and-gray stone, likely rhodonite-bearing rock

Rhodonite (MnSiO₃) in a manganese-rich metamorphic matrix; exact identification requires testing

Quartz Pebble

Silicon Dioxide (SiO2)

Basalt (Vesicular)

Basalt (Extrusive Volcanic Rock)

Blue Goldstone

Aventurine Glass (Silicon Dioxide with metal inclusions)

Garnetiferous Pegmatite

Pegmatite with Almandine Garnet and Muscovite

Map Jasper (Picasso Stone)

Metamorphosed Calcium Carbonate (Crystalline Limestone or Marble with Silicate inclusions/impurities)

Quartzite with Schist layers

Metamorphosed Quartz-rich Rock (Mixed Schist/Quartzite)

Rounded basalt cobble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with minor olivine or magnetite

Porphyritic Basalt (with Quartz or Calcite inclusion)

Porphyritic Basalt (Matrix: SiO2/MgO/FeO, Phenocryst: likely Quartz or Calcite)

Vesicular basalt (weathered volcanic rock)

Basalt, chiefly plagioclase feldspar, clinopyroxene, and possibly olivine/iron oxides

Migmatite

Migmatite (Mixed Rock)

Quartz

Silicon dioxide (SiO₂)

Tumbled blue glassy mineral, possibly sodalite or blue aventurine

Identification uncertain; likely sodalite (Na₈Al₆Si₆O₂₄Cl₂) or blue-dyed quartz/slag-like material

Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)

Elasmobranchii (fossil remains)

Greenstone (Epidosite / Chlorite Schist)

Metabasalt (often contains Epidote Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH) or Chlorite)

Travertine

Terrestrial Sedimentary Rock (CaCO3)

Tumbled quartz-rich rock, possibly jasperized quartz or quartzite

Quartz (SiO₂), likely with iron-oxide staining and minor feldspar or other silicate minerals; exact identification is uncertain from the photograph

Quartz

Silicon Dioxide (SiO2)

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Dark weathered pebble, likely basalt

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

Sandstone Clast

Arenite (primarily SiO2)

Sandstone / Chert Gravel

SiO2 (Silicon Dioxide based clastic sedimentary rock)

Glaucophane / Blue Schist

Glaucophane (Na2(Mg3Al2)Si8O22(OH)2)

Garnet-bearing Schist

Almandine Garnet [Fe3Al2(SiO4)3] in Micaceous Schist

Green Fuchsite in Quartz (sometimes called Green Aventurine)

Fuchsite (Chrome-rich Muscovite) K(Al,Cr)2(AlSi3O10)(OH)2 in Quartz SiO2

Coarse-grained Granite (Quartz and Feldspar dominated)

Granitoid (KAlSi3O8 – NaAlSi3O3 – CaAl2Si2O8 – SiO2)

Granite Boulder

Intrusive Igneous Rock

Sandstone (Micaceous Sandstone)

Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)

Citrine Quartz Geode

Silicon Dioxide (SiO2) with iron impurities

Banded Gneiss with Quartz Vein

Gneiss containing SiO2 (Quartz) intrusion

Tumbled chalcedony or quartz-rich stone

Microcrystalline quartz, SiO₂; possibly pale chert or chalcedony

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2

Tumbled green aventurine (probable)

Quartz aggregate, SiO₂, commonly containing fuchsite mica inclusions

Quartzite Pebble

Quartzite (SiO2-rich metamorphic rock)