Organic (Non Geological)

Obsidian

Volcanic Glass (Amorphous SiO2)

Seashell Fossil

Gastropoda fossil

Painted Sandstone

Sandstone (clastic sedimentary rock) with acrylic/artistic coating

Obsidian

Volcanic Glass (predominantly SiO2)

Black Obsidian

Obsidian (Amorphous volcanic glass, SiO2)

Iron-stained quartz-rich rock (likely ironstone/quartz vein material)

Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite; precise rock type cannot be confirmed visually

Gemstone bead necklace, likely mixed tourmaline and quartz

Probable schorl/dravite tourmaline with quartz or smoky quartz; exact identification requires testing

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide, SiO2)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Quartzite Pebble

Quartzite

Limestone Concretion

Calcium Carbonate Concretion (CaCO3)

Tumbled green aventurine (probable)

Quartzite dominated by quartz (SiO₂), with green fuchsite mica inclusions

Red coral beads (possibly dyed or imitation coral)

Corallium spp. skeleton, composed mainly of calcium carbonate (calcite); exact material cannot be confirmed from the image

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Fossil Bivalve / Ostreid Shell (Hag Stone / Perforated Pebble)

Phylum Mollusca, Class Bivalvia

Bull Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Emerald in Matrix

Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities

Siltstone with Fossil Cast

Sedimentary Rock (Siltstone / Fine-grained Sandstone)

Navajo Sandstone

Navajo Sandstone (primarily quartz arenite)

Glauconite (Greensand Articulated Sandstone)

Glauconite ((K, Na)(Fe, Al, Mg)2(Si, Al)4O10(OH)2)

Pyrite

Pyrite (Iron sulfide, FeS₂)

Fossilized Oyster Shell

Ostreidae (Calcium Carbonate - CaCO3)

Beaded blue-and-green gemstone jewelry

Likely dyed or treated chalcedony/agate and green aventurine or glass-like stone; exact identification requires testing

Dinosaur Bone (Fossilized Bone)

Permineralized Dinosaur Bone (Bio-apatite replaced by quartz/silica)

Fossilized Dinosaur Bone

Permineralized Vertebrate Bone (Apatite/Quartz replacement)

Quartzite

Metamorphic Quartzite (SiO2)

Slag

Glassy silicate byproduct (anthropogenic material)

Quartzite

Quartzite (primarily SiO2)

Common Opal (Potch)

Opal (Hydrated silica, SiO2·nH2O)

Quartzite

Quartzite (primarily SiO2)

Obsidian

Volcanic Glass (Rich in SiO2)

Obsidian

Volcanic Glass (SiO2)

Black Obsidian

Amorphous volcanic glass (SiO2)

Ironstone concretion (possible limonite/goethite-rich piece)

Iron-oxide-rich ironstone; commonly composed of goethite (FeO(OH)) and/or limonite

Polished orbicular jasper (likely ocean jasper)

Microcrystalline quartz (SiO₂), chiefly chalcedony with iron oxides and other silicate inclusions

Fossiliferous Limestone / Fossil Fragment

Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)

Quartzite

Metamorphic Quartzite (SiO2)

Likely polished chalcedony or agate cabochon pendant

Microcrystalline quartz, SiO₂ (chalcedony/possibly banded agate)

Carved pyrite frog or toad

Pyrite (iron disulfide, FeS₂), likely a carved massive aggregate

Fossil bone fragment, likely vertebrate limb or rib bone

Fossilized bone (apatite-rich hydroxyapatite, Ca₅(PO₄)₃OH); exact taxon indeterminate

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)