Anthropogenic Material

Flint

Microcrystalline Quartz (SiO2)

Coquina

Biogenic Limestone (Coquina)

Polished greenstone (likely serpentine or nephrite jade)

Serpentine-group mineral aggregate, commonly antigorite/lizardite; possible nephrite, a tremolite–actinolite amphibole aggregate

Serpentinite (serpentinized ultramafic rock), possibly with chromite

Serpentine-group minerals, chiefly lizardite and chrysotile; commonly derived from peridotite or pyroxenite, with possible chromite and magnetite

Pink microcline feldspar (likely amazonite-type feldspar)

Microcline, KAlSi₃O₈ (potassium feldspar)

Quartz-veined metamorphic cobble

Likely quartzite or quartz-rich metasedimentary rock; veins predominantly quartz (SiO₂)

Weathered quartz-rich rock, possibly quartzite or chert

Quartz (SiO₂), likely in a quartzite matrix; exact identification is uncertain from the image

Dendritic jasper (brecciated or orbicular jasper)

Microcrystalline quartz (SiO₂) with iron-oxide inclusions

Biotite-rich schist with garnet-like inclusion

Mica schist; predominantly muscovite/biotite mica, quartz, and feldspar, with a possible garnet or weathered mafic fragment

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

Sandstone Clast

Arenite (primarily SiO2)

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Faceted clear gemstone in an ornate ring

Likely colorless cubic zirconia (zirconium dioxide, ZrO₂); the image is insufficient to distinguish it from diamond or glass

Faceted Gemstones (Mixed)

Various (e.g., Corundum, Beryl, Quartz, or synthetic equivalents)

Pink quartz-like tumbled stone (possibly dyed quartz or pink chalcedony)

Quartz, SiO₂; appearance may also fit dyed quartzite or pink chalcedony

Quartz vein material

Quartz (SiO₂), likely milky quartz with iron-oxide staining

Jasper or Agatized material

Microcrystalline Quartz (SiO2)

Fossil oyster shell

Fossilized bivalve, likely an oyster (family Ostreidae); exact genus and age are indeterminable from the image

Tumbled quartz or chalcedony (uncertain)

Quartz, SiO₂; possibly cryptocrystalline chalcedony

Carved opalite pendant

Opalite (man-made opalescent glass; not a natural mineral)

Petrified Wood

Silicified Wood (SiO2)

Polished dark stone, possibly obsidian

Unidentified polished specimen; possibly volcanic glass (obsidian, silica-rich natural glass)

Tumbled chert or jasper pebble

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

Fossilized Wood

Petrified Wood (Silicified Wood)

Petrified Wood

Silicified wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Flint

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified wood (SiO2)

Likely calcite-rich limestone

Calcite (CaCO₃), likely in a carbonate rock; exact identification is uncertain from the image alone

Mixed river gravel (likely alluvial sediment)

Unconsolidated polymictic gravel; rock fragments of varied composition

Likely rough amber

Amber (fossilized tree resin; composition varies, commonly dominated by polymerized terpenoids)

Polished agate/geode slab

Banded chalcedony (microcrystalline quartz, SiO₂), likely with quartz crystals

Rounded limestone pebble

Limestone, composed chiefly of calcite (CaCO₃)

Diamond

C

Chert (Flint)

Sedimentary Cryptocrystalline Quartz (SiO2)

Diamond (or Diamond Simulant like Cubic Zirconia)

Carbon (C) - if Diamond; Zirconium dioxide (ZrO2) - if Cubic Zirconia

Serpentinite with green serpentine inclusion

Serpentinite; serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile, with possible magnetite

Red jasper flake/tool blank

Jasper, microcrystalline quartz (SiO₂), colored by iron oxides

Blue polished cabochon, likely dyed agate or chalcedony

Chalcedony (microcrystalline quartz, SiO₂); exact material cannot be confirmed from the image

Glass

Amorphous Silicon Dioxide (SiO2)

Diamond

Carbon (C)