Man Made (Synthetic Rock)

Granite with Orthoclase and Hematite Staining

Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)

Basalt

Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8

Basalt

Basalt (principally composed of pyroxene and plagioclase feldspar)

Granite Cobble

Granite (Phaneritic Quartz-Feldspar Felsic Rock)

Basalt (River Pebble)

Mafic volcanic rock (primarily Plagioclase feldspar and Pyroxene)

Basalt (River Cobble)

Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)

Basalt (with possible quartz veinsing)

Basalt

Basalt with Scoria/Vesicular Texture

Vesicular Basalt (Iron-rich/Oxidized)

Sandstone (likely Arkose or Quartz Sandstone)

Clastic sedimentary rock (primarily SiO2)

Chert (Gravel Bit)

Microcrystalline silica (SiO2)

Banded Agate

Chalcedony / Silicon Dioxide (SiO2)

Sandstone (with minor quartz and possible clay components)

Clastic Sedimentary Rock (SiO2 dominated)

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

Gossan with Copper Carbonate (Chrysocolla/Malachite)

Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Epidote

Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Blue Howlite (Dyed)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Jasper Breccia

Silicon Dioxide (SiO2) with impurities

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Quartz (Milky or Cloudy variety)

Silicon Dioxide (SiO2)

Picture Jasper

Silicon Dioxide (SiO2)

River Pebbles (Stream-rounded rocks)

Fluvial Detritus (varied mineralogy)

Chert (Chert Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Coquina Jasper

Fossiliferous Chalcedony (SiO2)

Labradorite (Larvikite variety)

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8 with Monzonite/Syenite matrix

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Ironstone Concretion

Limonitic/Hematitic Concretion

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Dyed Agate

Chalcedony (Silicon Dioxide, SiO2)

Bumblebee Jasper

Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)

Sand Dollar Fossil

Echinoidea (Clypeasteroida)

Coral Fossil (Favosites type)

Phylum Cnidaria, Class Anthozoa (often CaCO3 - Calcium Carbonate)

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Garnet in Matrix (Eclogite)

Eclogite, featuring Almandine or Pyrope Garnet [X3Y2(SiO4)3]

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock including secondary mineral infills)

Amethyst (Agate/Chalcedony variety)

Silicon Dioxide (SiO2) with iron impurities

Sandstone Concretion

Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)