Organic (Biological Specimen)

Rounded pale pebble, likely limestone

Micritic limestone, primarily calcite (CaCO₃)

Polished fossiliferous limestone (likely crinoidal or shell-rich limestone)

Bioclastic limestone, primarily calcite (CaCO₃), containing fossil fragments

Polished fossil coral

Fossilized colonial coral, commonly tabulate or rugose coral; calcite (CaCO₃) replacement

Orbicular/mafic river pebble with dark dendritic mineral patterns

Likely altered basalt or andesite; dark markings may be manganese-oxide dendrites (MnO₂-rich coatings)

Fossil coral or shell fragment

Indeterminate calcareous fossil; likely aragonite or calcite (CaCO₃)

Banded chert or flint pebble

Microcrystalline quartz (SiO₂), likely chert/flint with pale silica bands

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Paper (Cellulose)

Cellulose (C6H10O5)n

Chert (Flint/Jasper)

Microcrystalline Quartz (SiO2)

Fossil bivalve shell

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

Fossil coral limestone

Fossilized colonial coral, commonly tabulate or rugose coral in calcite-rich limestone (CaCO₃)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Dinosaur Bone (Petrified/Agatized)

Permineralized Dinosauria Bone (Silicate Replacement)

Banded limestone or marble

Calcite-rich carbonate rock; likely veined limestone, possibly low-grade marble (CaCO₃)

Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil

Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment

Fossilized bivalve shell fragment

Calcitic shell material, commonly Arca or related marine bivalve; primarily CaCO₃

Sandstone with Foliose Lichen

Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)

White aragonite (coralloid/botryoidal aragonite)

Aragonite, CaCO₃; orthorhombic polymorph of calcite

Likely flint/chert fragments

Microcrystalline quartz (SiO₂), possibly fossil-bearing chert

Fossilized bivalve shell

Fossil mollusk, likely an oyster or similar cemented bivalve; original shell mostly calcite (CaCO₃)

Calcite

Calcium Carbonate (CaCO3)

Weathered granite or granitic gneiss boulder

Granite–gneiss; chiefly quartz, feldspar, and mica

Yellow-brown chert or silicified rock

Microcrystalline quartz (SiO₂), possibly iron-stained chert

Shell fossil or shell fragment

Likely a bivalve shell, composed mainly of calcium carbonate (aragonite/calcite); exact species cannot be determined from one photo

Weathered sandstone

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

Vesicular Basalt (Scoria)

Basalt with vesicular texture

Chert / Chalcedony Nodule

Silicon Dioxide (SiO2)

Fossil shell fragment

Indeterminate mollusk shell; likely gastropod or bivalve, composed mainly of calcium carbonate (aragonite/calcite)

Burmese Amber (Burmite)

Burmite (C10H16O)

Fossiliferous conglomeratic sandstone

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

Fossilized tooth, likely a shark tooth

Fossil vertebrate tooth; exact taxon uncertain, possibly Otodus/Carcharodon-type

Potassium-Rich Silicate Clay (inferred from biological context)

Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)

Weathered fossiliferous limestone, likely coral or shell fragment

Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image

Weathered limestone pebble

Limestone, primarily calcite (CaCO₃)

Fossilized mammalian tooth fragment

Likely a fossil molar or premolar; exact taxon cannot be determined from the image

Marine invertebrate fossils (Brachiopods and Gastropods)

Phylum Brachiopoda and Class Gastropoda

Likely limestone or calcareous fossil fragment

Calcite-rich carbonate rock; possibly bioclastic limestone (CaCO₃)

Tumbled brown chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Chert (containing fossil leaf impression)

Microcrystalline silicon dioxide (SiO2)

Likely fossil tooth or tooth fragment

Indeterminate fossilized vertebrate tooth; possibly shark or marine reptile, identification uncertain from the image

Orange Calcite (likely polished specimen)

Calcite

Lichen-covered granite

Granite, chiefly quartz–feldspar–mica; surface colonized by lichens