Organic Material (Likely A Fruit Or Berry)

Limestone Pebble

Calcite-rich Sedimentary Rock (CaCO3)

Chert or flint

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)

Banded Chert

Microcrystalline Quartz (SiO2)

Quartz-veined metamorphic rock, likely greenschist or altered basalt

Chlorite–actinolite schist or metabasalt with a milky quartz vein

Orange calcite

Calcite (CaCO₃), likely honey/orange calcite

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)

Quartzite

Quartzite (SiO2)

Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock

Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt

Banded Chert (or Flint)

Microcrystalline Quartz (SiO2)

Vesicular basalt (weathered volcanic rock)

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

Lichen-covered graywacke or granitic glacial cobble

Indeterminate; likely quartz–feldspar–mica rock, possibly weathered granite or granodiorite

Decorative polished pebbles

Likely mixed quartz-rich lithologies, including quartzite, jasper, and/or basalt

Tumbled quartz-rich pebble

Quartz (SiO₂), likely with iron-oxide staining and minor feldspar

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂), colored by hematite/goethite; possibly brecciated jasper

Likely galena-bearing ore

Galena (PbS), possibly mixed with quartz or carbonate gangue

Tumbled greenstone (likely serpentine)

Serpentinite; mainly serpentine-group minerals, commonly antigorite, lizardite, or chrysotile

Fossilized oyster shell

Bivalvia; likely an oyster (Ostreidae), partly mineralized with calcite

Quartzite

Quartzite (primarily SiO2)

Petrified Wood

Silicified Wood (SiO2)

Crushed Stone (Likely Limestone or Granite)

Calcium Carbonate (CaCO3) for Limestone / Quartz and Feldspar for Granite

Polished brown jasper (likely ocean or brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides

Likely iron-rich slag or weathered ironstone

Hematite–goethite-rich material (Fe₂O₃/FeO(OH)); possibly industrial iron slag

Likely basalt (possibly a dark beach pebble)

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine

Mixed river-worn rock and mineral collection

Mostly quartz/quartzite, feldspar-bearing granitoid, chert, and mafic volcanic rocks; exact species vary by pebble

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite

Green tourmaline crystal (likely elbaite)

Elbaite tourmaline, a complex borosilicate: Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Banded sandstone pebble

Quartz-rich lithic sandstone; exact provenance and composition require testing

Honey calcite (likely rough cleavage fragment)

Calcite, calcium carbonate (CaCO₃)

Likely galena-bearing ore specimen

Galena (PbS), possibly with quartz or calcite gangue

Petrified Wood

Silicified Wood (SiO2)

Carnelian (Orange Chalcedony)

Silicon Dioxide (SiO2)

Weathered quartzite cobble

Quartzite, predominantly crystalline SiO₂

Vesicular volcanic scoria (likely basaltic scoria)

Scoria; predominantly iron- and magnesium-rich silicate glass with plagioclase, pyroxene, and possible olivine

Tumbled brown stone, likely jasper or chert

Microcrystalline quartz (SiO₂), probably iron-stained jasper/chert

Milky quartz (rough quartz specimen)

Quartz, silicon dioxide (SiO₂)

Weathered vuggy quartz-rich rock (probable silicified limestone or quartz breccia)

Microcrystalline quartz (SiO₂) with calcite (CaCO₃), iron oxides, and minor clay minerals

Tumbled dark igneous rock, likely basalt

Basalt; commonly composed of plagioclase feldspar, pyroxene, and olivine

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Tumbled black stone, likely basalt or obsidian

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or dark volcanic glass (obsidian)

Fossil Shark Tooth

Carcharodon carcharias (modern/recent) or similar Lamniform fossil