Mineraloid (Man Made)

Tumbled kambaba jasper (likely)

Kambaba jasper, a silica-rich microcrystalline quartz aggregate, commonly containing fossilized cyanobacterial structures and dark green amphibole/pyroxene minerals

Diamond (in a jewelry setting)

Cubic Carbon (C)

Nacre (Mother of Pearl)

Nacre (Biogenic Aragonite/Calcite composite, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)

Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)

Likely weathered sandstone fragment

Sandstone, composed mainly of quartz (SiO₂) and feldspar grains in a clay, silica, or iron-oxide cement

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

Quartzite

Metamorphic Quartz Arenite

Tumbled green glassy mineral, possibly aventurine or fluorite

Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)

Diamond

Carbon (C)

gemstone

Pearl

Calcium Carbonate (CaCO3) with Conchiolin

Black obsidian

Volcanic glass; predominantly silica-rich, noncrystalline SiO₂

igneous

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Sandstone

Arenite (specifically sublithic or quartz arenite)

Quartzite

Metamorphic Quartzite (SiO2)

Pyrite

Iron Sulfide (FeS2)

Diamond (Cluster Ring)

Carbon (C)

Diamond

Carbon (C)

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Chert (Chert / Flint)

Microcrystalline Quartz (SiO2)

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

igneous

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Rough Diamond

Diamond (pure Carbon, C)

Diamond

Native Carbon (C)

Diamond

Carbon (C)

Pearl (Imitation or Cultured)

Calcium Carbonate (Aragonite/Calcite) - CaCO3

Mineraloid (Organic)

Sandstone

Arenite (SiO2 primarily)

Limestone

Calcium Carbonate (CaCO3)

Serpentinite (likely antigorite-rich)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite and minor chromite

Diamond

Diamond (Pure Carbon, C)

Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)

Quartz, silicon dioxide (SiO₂)

Veined dark metamorphic rock, likely serpentinite

Serpentinite, predominantly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible quartz, calcite, and magnetite veins

Likely graphite-rich schist

Graphitic schist; chiefly graphite and quartz/mica

Sandstone

Sedimentary Rock (Quartz arenite)

Quartzite

Quartzite (Metamorphic Quartz Sandstone)

Amber

Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)

Organic Mineraloid

Likely blue glass or synthetic gemstone jewelry

Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass

gemstone

Pearl (in a decorative hair comb setting)

Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin

Organic Mineraloid

Rough Diamond

Pure Carbon (C)