Mineraloid (Human Made Geological Specimen)

Tumbled blue glassy mineral, possibly sodalite or blue aventurine

Identification uncertain; likely sodalite (Na₈Al₆Si₆O₂₄Cl₂) or blue-dyed quartz/slag-like material

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Amber (Black)

Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)

Black obsidian arrowhead

Obsidian (volcanic glass), primarily silica-rich rhyolitic composition

Petoskey Stone / Rugose Coral Fossil

Hexagonaria percarinata

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Chert Nodule (Flint)

Chert (Silicon Dioxide, SiO2)

Sandstone Concretion

Sedimentary Clastic Rock (Silicate-rich)

Tumbled gray feldspar-rich stone, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially fine-grained granite or quartzite

Polished pink-and-white quartz bead bracelet

Quartz (SiO₂), likely rose quartz and milky quartz; some orange beads may be iron-stained quartz or pale carnelian

Mother of Pearl (Nacre) / Shell Fragment

Biogenic Calcium Carbonate (Aragonite and Conchiolin)

Flint (Chert)

Silicon Dioxide (SiO2)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Tumbled brown chalcedony (likely jasper or agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining

Aura Quartz (Pink/Rose Aura Quartz)

Silicon Dioxide (SiO2) bonded with Platinum and/or Silver

Chert / Yellow Jasper

Microcrystalline Quartz (SiO2)

Limonite with Quartz (Gossan)

Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)

Chert (Common Opal/Chalcedony)

Microcrystalline Quartz (SiO2)

Granodiorite

Intrusive Igneous Rock

Chert (Flint variety)

Chert (SiO2)

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Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Blue Apatite

Calcium phosphate mineral, Ca5(PO4)3(F,Cl,OH)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Jasper

Silicon dioxide (SiO2) with impurities

Red Slag Glass

Amorphous Silica (Industrial byproduct with metallic oxide dopants)

Granite with Cupules / Bedrock Mortars

Granite (felsic intrusive plutonic rock)

Blue Dyed Agate Slice

Silicon Dioxide (SiO2) with artificial pigment

Chert (variations include Flint/Jasper)

Cryptocrystalline Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper)

Microcrystalline Quartz (SiO2)

Polished crescent-shaped stone pendant

Likely black jade, basalt, or other dark silicate stone; exact identification requires testing

Quartzite

Metamorphic Quartzite (SiO2)

Likely limestone or calcareous fossil fragment

Calcite-rich carbonate rock; possibly bioclastic limestone (CaCO₃)

Belemnoit (Fossil)

Belemnoidea (Order), Rostrum / Guard

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)

Tumbled red jasper with a quartz vein

Jasper (microcrystalline quartz, SiO₂), likely crossed by milky quartz

Polished orange agate or chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/agate

Dumortierite in Quartz

Dumortierite (Al6O3(BO3)(SiO4)3) with Quartz (SiO2)

Chert (Lithic flake / Arrowhead fragment)

Microcrystalline Quartz (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)