Sedimentary (Biogenic Sediment Or Biological Remain)

Fossiliferous conglomeratic sandstone

Clastic sedimentary rock, likely quartz–feldspar sandstone with lithic granules and shell/bioclastic fragments

Fossilized Syringopora (Piping Organ Coral)

Syringopora (Extinct Genus of Tabulate Coral)

Chert (Siliceous Mudstone variant)

Microcrystalline quartz (SiO2)

Ironstone concretion (possibly pyrite-bearing)

Iron-rich sedimentary concretion, likely composed of goethite/limonite with possible pyrite

Possible fossilized shell or fossil fragment

Indeterminate; possibly a small brachiopod or gastropod fossil in mineralized matrix

Fossil Crab

Decapoda (likely Avitelmessus or Raninidae family)

Chert Nodule (Fossiliferous Chert)

Microcrystalline Quartz (SiO2)

Likely quartz-rich stone or shell fragment

Uncertain; possibly quartz (SiO₂) or a calcareous shell fragment (CaCO₃)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Concretion

Siderite or Ironstone Concretion

Amber

Succinite (approximate formula C10H16O)

Shale with Trace Fossils

Fissile mudrock (Shale)

Shale

Shale (Lutite)

Shale

Fissile mudstone (rich in clay minerals and quartz)

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

Megalodon Shark Tooth

Otodus megalodon

Fossilized Shark Tooth (Fragment) in Matrix

Elasmobranchii (subclass)

Tufa

Calcareous Tufa (CaCO3)

Sandstone with Quartz Vein

Arenite with Crystalline Silica (SiO2)

Weathered sandstone boulder

Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement

Fossil bivalve shell

Calcitic aragonitic bivalve mollusk shell; exact taxon cannot be determined from the image

Weathered sandstone

Quartz-rich clastic sandstone, chiefly SiO₂ with minor feldspar, lithic grains, and iron-oxide/clay cement

Chert / Flint (with Iron Staining)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Sandstone Concretion

Ferruginous Sandstone Concretion

Weathered flint or chert fragment

Microcrystalline quartz (SiO₂), commonly called chert or flint

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Amber

Succinite (specifically for Baltic amber; general formula C10H16O)

Shale

Laminated Mudstone

Massive calcite (likely limestone-derived calcite)

Calcite, calcium carbonate (CaCO₃); possibly a chalky limestone fragment

Sandstone (Water-worn)

Arenite

Flagstone paving (likely sandstone or limestone)

Clastic sandstone or carbonate limestone; exact identification requires testing

Weathered iron-rich concretion or sedimentary rock

Likely ferruginous sandstone or ironstone concretion; exact identification is not possible from the image alone

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Desert Varnish (on Sandstone)

Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)

Fossilized Brachiopod Shell

Order Spiriferida (likely)

Iron-stained quartz/chert pebble

Microcrystalline quartz (SiO₂) with iron-oxide minerals, chiefly goethite/limonite

Brown shale or mudstone fragment

Likely fissile claystone/shale, composed mainly of compacted clay minerals, quartz, and minor iron oxides

Fossil-bearing rock, likely a fossilized shell or coral fragment

Unidentified calcitic fossil in a carbonate matrix (likely calcite, CaCO₃)

Shale or Siltstone

Fine-grained siliciclastic sedimentary rock

Sandstone Concretion

Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)