Mineraloid (Human Made Geological Specimen)

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, likely with minor calcite or nepheline

Tumbled yellow jasper or chert

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

Tumbled brown jasper

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

Kidney Stone (Calcium Oxalate / Uric Acid)

Calcium Oxalate Monohydrate (Whewellite) / Calcium Oxalate Dihydrate (Weddellite)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite / Chlorapatite [Ca5(PO4)3(F,Cl,OH)]

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Tumbled purple stone, possibly lepidolite-bearing rock or dyed quartzite

Uncertain from image; possible quartz (SiO₂) with purple mica, or artificially dyed silicate

Tumbled purple quartz, possibly amethyst

Quartz (SiO₂), likely iron-colored amethyst or purple chalcedony

Chert (with nodule)

Microcrystalline Quartz (SiO2)

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Beads (likely glass or man-made material)

N/A (artificial material)

Brown Chert

Microcrystalline Quartz (SiO2)

Fossil coral fragment

Fossilized colonial coral, commonly *Hexagonaria* (often called Petoskey stone) or related scleractinian/tabulate coral

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Small rounded mineral pebble, possibly quartz

Uncertain; likely microcrystalline or crystalline SiO₂ (quartz), potentially with iron-oxide staining

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), opaque-to-translucent milky variety

Opal

Hydrated Silica (SiO2·nH2O)

Chert (Black Flint)

Silicon Dioxide (SiO2)

Chert

Sedimentary cryptocrystalline quartz (SiO2)

Tumbled white stone, possibly quartz or marble

Uncertain; likely quartz (SiO₂) or calcite-rich marble (CaCO₃)

Tumbled honey calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Vesicular basalt (possibly slag-contaminated)

Basalt; chiefly plagioclase and pyroxene, with possible olivine and secondary minerals

Pearl (Biogenic Mineral)

Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3

Polished fossiliferous chert or silicified limestone pebble

Microcrystalline quartz (SiO₂), possibly with calcite and iron-oxide inclusions

Obsidian

Volcanic Glass (Amorphous SiO2)

Polished vesicular basalt (likely scoriaceous basalt)

Basalt, aphanitic mafic volcanic rock; chiefly plagioclase, pyroxene, and iron-rich oxides

Smoky Quartz

Silicon Dioxide (SiO2)

Polished/tumbled jasper, likely brecciated jasper

Jasper: microcrystalline quartz (SiO₂), with iron-oxide and other mineral impurities

Bismuth crystal

Bismuth (Bi), commonly laboratory-grown hopper crystal

Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Chert or heavily weathered flint

Microcrystalline quartz (SiO₂), likely chert/flint

Quartz crystal fragment (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled chalcedony or quartz pebble

Microcrystalline quartz, SiO₂ (likely chalcedony); exact identification is uncertain from the image

Amber (likely raw amber)

Fossilized tree resin; organic mineraloid, commonly containing succinite (not a true mineral)

Small tumbled orange-brown mineral fragment

Indeterminate; possibly iron-stained quartz, carnelian, or orange calcite

Botryoidal chalcedony with iron-oxide staining

Microcrystalline quartz (SiO₂), likely iron-oxide-bearing chalcedony

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Tumbled chalcedony or quartz pebble

Microcrystalline quartz (SiO₂), likely orange chalcedony/carnelian