Sedimentary (Fossil)

Pyrite Sun (Pyrite Dollar)

Iron Disulfide (FeS2)

Fossilized Shark Tooth

Carcharodon (Galeocerdo sp. or Lamniform)

Dendritic Agate (Tree Agate)

Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions

Fossilized Wood (Petrified Wood)

Silicified Wood (primarily quartz/chalcedony replacing organic matter)

Slate

Slate

Amber

Succinates (C10H16O)

Amber

Succinite (Organic Gemstone)

Amber

Succinite (C10H16O)

Amber

Succinite (C10H16O)

Amber

Succinite (C10H16O)

Amber

Fossilized Tree Resin

Amber

Succinite

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Sandstone

Sandstone (lithified arenite/wacke)

Weathered quartz-rich cobble, possibly quartzite or feldspar-rich granite

Quartz–feldspar aggregate; identification is uncertain from the photograph

Amber

Succinite

Iron-rich brown stone, possibly weathered chert or ironstone

Undetermined; likely iron-oxide-bearing silica-rich rock (chert/ironstone)

Riverstone (Sandstone Pebble)

Arenite (SiO2 with various lithic fragments)

Red Sandstone

Arenite (primarily Quartz and Feldspar with Iron Oxide cement)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Flower Agate

Silicon Dioxide (SiO2) with Plume Inclusions

Jasper-rich Quartzite with Quartz Veining

Silicon Dioxide (SiO2) with Ferric Oxide inclusions

Vesicular volcanic rock, likely pumice or scoria

Vesicular rhyolitic–andesitic volcanic rock; predominantly silicate glass with feldspar and possibly pyroxene

Dendritic Quartz Pebble

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Desert Rose (Baryte or Selenite variant)

Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions

Rounded quartz-rich pebble, possibly granite or gneiss

Indeterminate granitoid; likely quartz–feldspar–biotite aggregate

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Anthracite Coal

Anthracite (Carbon-based solid)

Petrified Wood (Silicified Wood)

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

Petrified Wood

Silicified Wood (SiO2)

Tumbled chalcedony (likely moss or dendritic agate)

Microcrystalline quartz, SiO₂, with iron-oxide inclusions

Amber

Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Tumbled pegmatitic granite

Granite, chiefly quartz–feldspar–mica; likely altered pegmatite

Amber

Succinite (specific to Baltic amber), fossilized tree resin

Amber

Succinite (fossilized resin)

Amber

Succinite (Approximate formula: C10H16O)

Amber

Succinite (Approximate formula: C10H16O)

Vesicular volcanic rock, likely pumice or scoria

Pumice (highly vesicular rhyolitic–dacitic volcanic glass) or scoria (vesicular basaltic rock)

Dendritic Agate

Chalcedony (Silicon Dioxide) with Manganese or Iron Oxide inclusions

Dendritic Quartz

Silicon Dioxide (SiO2) with Manganese Oxide inclusions

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)