Mineraloid (Human Made Geological Specimen)

Pyrite in Matrix

Iron Sulfide (FeS2)

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (primarily SiO2)

Blue Opal Inlay (Simulated/Lab-created)

Hydrated Amorphous Silica (SiO2·nH2O) with polymer resin

Common Opal (Green Opal / Pistachio Opal)

Hydrated silica (SiO2·nH2O)

Polished black-and-white marble pyramid

Calcite-dominant marble, likely a decorative variety of calcite marble

Crushed stone aggregate

Mixed lithic aggregate; individual fragments cannot be identified from the image

Green gemstone ring, possibly emerald

The green stone may be emerald (beryl, Be₃Al₂Si₆O₁₈), but the photo cannot confirm its identity; the setting appears to be silver-colored metal.

Tumbled quartz (likely milky/rose quartz)

Quartz, silicon dioxide (SiO₂)

Mixed Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Carved opalite pendant

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

Tumbled jasper (likely ocean or picture jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral impurities

Flint or chert projectile point

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Tumbled jasper, likely picture or brecciated jasper

Microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities

Obsidian

Volcanic Glass (SiO2)

Green obsidian (likely molded or heat-treated glass-like specimen)

Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxidized

Tumbled black obsidian (likely)

Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)

Yellow Chert (Chalcedony)

Microcrystalline Quartz (SiO2)

Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Obsidian Arrowhead

Volcanic Glass (predominantly SiO2)

Polished gray pebble

Likely quartz-rich chert or fine-grained quartzite; exact identification is uncertain from the photograph

Gold Sheen Obsidian

Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)

Painted or coated beach pebble

Uncertain; likely quartz-rich sandstone, quartzite, or a rounded silicate pebble with turquoise-colored surface coating

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Polished honey calcite point

Calcite (calcium carbonate, CaCO₃), likely honey/yellow calcite

Tumbled brown banded jasper

Microcrystalline quartz (SiO₂), commonly chalcedony with iron-oxide inclusions

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)

Blue opal heart cabochon

Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite

Tumbled green aventurine (probable)

Quartz, SiO₂, with green fuchsite mica inclusions

Polished goniatite fossil limestone

Goniatite-bearing Devonian–Carboniferous limestone; fossil cephalopod shells (Goniatitida) in calcite-rich matrix

White quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Iron-stained chert or silicified ironstone

Microcrystalline quartz (SiO₂), likely limonite/goethite-bearing chert

Flint or chert flake

Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities

Human Skin (Epidermis/Dermis)

Integumentary tissue (High content of hydroxyapatite in bones, though the surface is biological)

Obsidian (likely snowflake-free black variety)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Polished black stone pendant

Likely black obsidian or black tourmaline; exact identification is uncertain from the photograph

Polished/tumbled brown jasper (likely weathered chert)

Microcrystalline quartz, SiO₂, with iron-oxide impurities

Granite Pebble

Felsic intrusive igneous rock

Obsidian

Obsidian (Volcanic Glass)

Jasper Pebble

Microcrystalline Quartz (SiO2)