Mineraloid (Anthropogenic)

Slag (Industrial Byproduct)

Ferro-silicate glass (Slag)

Iron Slag

Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)

Goldfish Cracker (Culinary Mimic)

Cibus aurum (Commonly composed of Enriched Wheat Flour and Cheddar Cheese)

Slag

Ferrous Slag (Siliceous industrial waste)

Sea Glass (Uranium/Vaseline Glass variant)

Silicon Dioxide (SiO2) with trace Uranium Oxide (U3O8)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Terracotta (Man-made ceramic brick fragment)

Baked clay / High-iron ceramic (Silicate-based ceramic)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Sea Glass (Teal/Turquoise)

Amorphous Silica (SiO2) with trace metal oxides

Slag Glass

Amorphous Silica / Glass Slag

Sea Glass (Turquoise/Aqua)

Amorphous Silica (SiO2) with transition metal dopants

Aventurine (likely Green Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Concrete Fragment

Hardened Portland Cement Composite

Uncertain dark gray-brown rock fragment

Indeterminate; possibly weathered chert, serpentine, or iron-stained quartzite

Fossilized oyster shell in limestone

Bivalvia fossil; chiefly calcite (CaCO₃)

Polished banded calcite/aragonite tower

Calcite (CaCO₃), possibly aragonite (CaCO₃)

Citrine

Silicon Dioxide (SiO2)

Greenstone (Metabalt)

Chlorite-actinolite schist (Greenstone)

Dalmatian jasper

Quartz-bearing, orbicular microcrystalline silica (commonly sold as “Dalmatian jasper”; often an altered porphyritic igneous rock)

Tumbled brown-and-black stone, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase, pyroxene, and possibly olivine or iron oxides

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

River Pebbles (Stream-rounded rocks)

Fluvial Detritus (varied mineralogy)

Polished bumblebee jasper (likely)

Calcite–sulfur-rich volcanic breccia, commonly sold as “bumblebee jasper”

Iron-rich metamorphic rock, likely specular hematite-bearing schist

Hematite–quartz–mica schist (tentative)

Small quartz-rich stone, possibly granite fragment

Indeterminate; likely quartz (SiO₂) with feldspar and/or mica

Petrified Wood

Silicified Wood (SiO2)

Iron-stained metamorphic rock, likely schist or quartzite

Quartz–mica–iron oxide rock; probable muscovite/biotite schist or ferruginous quartzite

Chert Arrowhead

Cryptocrystalline Quartz (SiO2)

Tumbled lepidolite-rich pegmatite (probable)

Lepidolite, K(Li,Al)3(Si,Al)4O10(F,OH)2, in a granitic pegmatite matrix

Banded Gneiss (with Quartz Vein)

Gneiss (Metamorphic rock of varying mineralogy)

Labradorite

(Ca, Na)(Al, Si)4O8 (Calcium Sodium Aluminum Silicate)

Sand Grain (Quartz)

Silicon Dioxide (SiO2)

River Pebbles

Polymictic Gravel

Yellow-green aventurine or serpentine pendant

Most likely serpentine-group mineral (magnesium silicate), possibly quartz-rich aventurine

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Optical Calcite

Calcium Carbonate (CaCO3)

Black-and-white spotted jasper (likely dalmatian jasper), polished beads

Commercially called Dalmatian jasper; typically a feldspar-rich rock with dark inclusions, not true jasper (microcrystalline quartz). Exact composition cannot be confirmed from the image.

Small rounded pebble

Indeterminate lithic clast; likely weathered quartzite, sandstone, or chert

Weathered greenish rock fragment

Indeterminate; possibly epidote- or chlorite-bearing altered silicate rock

Rounded river pebble (likely weathered granite or metamorphic rock)

Indeterminate; possible granitic or quartz-rich lithology

Chalcopyrite

Copper Iron Sulfide (CuFeS2)