Organic Gem Material (Botanical)

Quartz-rich pegmatite (likely milky quartz with feldspar)

Pegmatitic quartz–feldspar rock; primarily SiO₂ quartz with K-feldspar/plagioclase

Granite (likely biotite granite)

Coarse-grained felsic plutonic rock composed mainly of quartz, alkali feldspar, plagioclase, and biotite/hornblende

Vesicular basalt (weathered river stone)

Basalt, chiefly plagioclase feldspar, pyroxene, and commonly olivine

Tumbled labradorite

Labradorite, calcium-rich plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Tumbled quartzite or quartz-rich river pebble

Quartzite, predominantly microcrystalline quartz (SiO₂), with iron-oxide and possible chlorite/epidote staining

Biotite granite (weathered granitic rock)

Granite, chiefly quartz (SiO₂), feldspar, and biotite mica

Polished black tourmaline (schorl)

Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Likely quartz-bearing metamorphic rock

Probably quartzite or quartz-rich schist; mainly quartz (SiO₂), possibly mica and feldspar

Mica schist fragment

Biotite–quartz–feldspar schist

Tumbled quartz pebbles

Quartz (silicon dioxide, SiO₂), commonly milky or translucent quartz

Mica-rich metamorphic rock, likely phyllite or schist

Quartz–mica schist/phyllite; chiefly muscovite or biotite mica with quartz and feldspar

Iron-stained quartz/pegmatite fragment

Quartz (SiO₂) with iron-oxide/hydroxide staining, possibly feldspar matrix

Greenstone pebble, likely altered basalt

Metabasalt/greenstone; commonly chlorite–epidote–actinolite with albite and iron oxides

Tumbled green beryl or glassy green gemstone

Likely beryl, Be₃Al₂Si₆O₁₈; possibly treated emerald or synthetic glass

Weathered sandstone pebble

Quartz-rich sandstone; chiefly SiO₂ with possible feldspar, mica, and iron-oxide cement

Weathered quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly iron-oxide stained

Quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂)

Fossiliferous Sandstone with Plant Remains

Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)

Chert (Chalcedony)

Microcrystalline Quartz (SiO2)

Gemstone ring (stones not reliably identifiable from the image)

Likely faceted yellow stones and clear stones set in a metal band; species and treatments are indeterminate visually

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Jasper

Silicon dioxide (SiO2) with impurities, microcrystalline quartz

Jasper

Microcrystalline Quartz (SiO2)

Mammoth Molar Fossil

Mammuthus primigenius (Tooth fragment)

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Travertine

Terrestrial Sedimentary Limestone (CaCO3)

Iron-stained chert or flint nodule

Microcrystalline quartz (SiO₂), likely chert with limonite/goethite staining

Blue apatite crystals

Apatite group, commonly fluorapatite (Ca₅(PO₄)₃F)

Likely colorless topaz

Topaz, Al₂SiO₄(F,OH)₂

Polished sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Tumbled mahogany obsidian

Volcanic glass, predominantly rhyolitic silica (SiO₂), with iron-oxide inclusions

Sapphire

Corundum (Al2O3)

Sedimentary Rock (Limestone or Siltstone pebble)

Sedimentary rock fragment

Tumbled rose quartz (probable)

Quartz, silicon dioxide (SiO₂), pink variety

Chrysocolla Chalcedony

Hydrated Copper Phyllosilicate (Cu,Al)2H2Si2O5(OH)4 + SiO2

Jasper

Jasper (Silicified microcrystalline quartz) - SiO2

Jasper

Silicon Dioxide (SiO2)

Red gemstone, likely ruby

Corundum (Al₂O₃), colored red by chromium; identity cannot be confirmed from the photo

Orange fire opal jewelry

Precious opal, hydrated amorphous silica (SiO₂·nH₂O)

Likely green aventurine quartzite

Aventurine quartz (quartzite), SiO₂ with mica/fuchsite inclusions

Fossil tooth

Mineralized vertebrate tooth; exact animal and species cannot be determined from the image

Red garnet crystal (possible almandine)

Garnet group; likely almandine, Fe₃Al₂(SiO₄)₃