Man Made

Gold ring with a dark, possibly gemstone setting

Gold alloy; the dark setting is not identifiable from the image

Faience and Carnelian in Egyptian Revival Jewelry

Faience (quartz frit) and Carnelian (chalcedony, SiO2)

Flint

Microcrystalline Quartz (SiO2)

White flint (chert)

Microcrystalline quartz, SiO₂

Likely chert (flint) fragment

Microcrystalline quartz, SiO₂

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Diamond

Carbon (C)

Rough Diamond

Native Carbon (C)

Diamond (in a cluster setting)

Crystallized Carbon (C)

Coquina

Bioclastic Limestone

Coquina

Bioclastic Limestone

Polished carnelian agate

Microcrystalline quartz (SiO₂), chalcedony variety; orange-red color commonly from iron oxides

Tumbled carnelian (reddish-orange chalcedony)

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

Polished jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with possible iron-oxide and other mineral inclusions

Note on Image Identification: Textile

N/A (Anthropogenic material)

Corundum (Sapphire/Ruby in Matrix)

Corundum (Al2O3)

Diamond Druzy (Crystalline Diamond)

Carbon (C)

Diamond

Diamond (pure native carbon, C)

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Turquoise-colored bead necklace (likely dyed howlite or magnesite)

Likely dyed Ca₂B₅SiO₉(OH)₅ (howlite) or MgCO₃ (magnesite); turquoise is CuAl₆(PO₄)₄(OH)₈·4H₂O

Possible ironstone concretion or weathered mineral nodule

Iron-oxide-rich concretion, likely goethite/limonite; identification uncertain from the photo

Fossil coral

Fossilized colonial coral, likely rugose or tabulate coral preserved in limestone

Flint (gray chert)

Microcrystalline quartz (SiO₂), a variety of chert

Polished brown jasper (likely iron-rich jasper)

Jasper, an opaque microcrystalline variety of quartz (SiO₂)

Basalt

Basalt

Fossilized Burrow

Trace fossil (Ichnogenus)

Faceted clear gemstone ring, likely quartz or glass imitation

Unidentified colorless faceted material; quartz (SiO₂) is possible, but the image cannot distinguish it from glass or another gem

Grey Chalcedony

Silicon Dioxide (SiO2)

Diamond (as featured in jewelry)

Diamond (C - pure carbon)

Coquina

Bioclastic Limestone

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Granite (with a dark inclusion or attached fragment)

Granite, mainly quartz, feldspar, and mica; the dark object cannot be identified confidently from the photo.

Black tumbled stone, possibly obsidian

Obsidian (natural volcanic glass; composition varies, typically silica-rich)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Fossil Sea Urchin (Echinoid)

Echinoidea fossil (often replaced by silica or calcite)

Chert (flint)

Microcrystalline quartz, SiO₂ (chalcedony/quartz)

Flint (chert)

Microcrystalline quartz, SiO₂

White marble

Calcite marble, predominantly CaCO₃

Chert (flint) fragment

Microcrystalline quartz (SiO₂), commonly called chert or flint

Pearl necklace

Pearl, primarily aragonite (CaCO₃) and conchiolin

Likely slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

Blue chalcedony cabochon (likely)

Chalcedony, microcrystalline SiO₂; possibly blue agate or common opal, which cannot be distinguished confidently from the image