Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Picture Jasper

SiO2

Sandstone

Arenite (primarily composed of SiO2)

Flint (or Chert)

Microcrystalline quartz (SiO2)

Fossilized bone or tooth fragment in rock matrix

Indeterminate vertebrate fossil; mineralized apatite (carbonate-fluorapatite) with silica/carbonate-rich matrix

Black Jasper

Silicon Dioxide (SiO2) with impurities

Polished brecciated jasper

Jasper, an opaque microcrystalline variety of chalcedony (SiO₂), with iron-oxide staining

Weathered volcanic rock, likely andesite or basalt

Fine-grained mafic to intermediate volcanic rock; likely basaltic andesite/andesite, composition dominated by plagioclase with pyroxene and/or olivine

Petrified Wood

Silicified Wood (SiO2)

Amber

Succinite (fossilized resin)

Black Onyx and Mother of Pearl

Cryptocrystalline Quartz (SiO2) and Nacre (Calcium Carbonate)

Fossil Shark Tooth

Chondrichthyes (Class)

Zebra Rock / Zebra Marble

Banded Limestone-Marble Transition

Iron-rich breccia or gossan rock

Goethite–hematite–limonite aggregate, possibly with chalcopyrite/malachite staining

Tumbled bloodstone (heliotrope), probable

Chalcedony (microcrystalline quartz, SiO₂) with iron-oxide inclusions

Yellow Sapphire

Corundum (Al2O3)

Bloodstone (Heliotrope)

Silicon Dioxide (SiO2) with inclusions of Iron Oxide or Chlorite

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Petrified Wood

Silicified Wood (SiO2)

Brown translucent mineral fragment, possibly iron-stained quartz or amber

Uncertain; likely quartz (SiO₂) with iron-oxide staining, though amber (fossilized resin) is possible

Chert (Jasper/Mudstone variety with Oxidation)

Silicon dioxide (SiO2)

Petrified Wood

Silicified Wood (Permineralized wood)

Rough Quartz (or Quartzite pebble)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

Opalite

Man-made glass (traditionally simulated Opal)

Lepidodendron Fossil (Scale Tree)

Lepidodendron

Chert (Holey Stone)

Microcrystalline Quartz (SiO2)

Tumbled amber

Amber (fossilized plant resin), commonly succinite; organic mineraloid

Chert (and its variety Flint)

Silicon dioxide (SiO2) / Microcrystalline quartz

Petrified Wood

Silicified wood (principally SiO2)

Petrified Wood / Fossilized Wood

Silicified Wood (Silicon Dioxide - SiO2)

Petrified Wood

Silicified Wood (SiO2)

Graphite-rich metamorphic rock (graphitic schist)

Graphitic schist; chiefly graphite (C), quartz (SiO₂), and mica minerals

Milky Quartz

Silicon Dioxide (SiO2)

Asphalt aggregate

Human-made bituminous asphalt containing crushed silicate rock aggregate

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Tumbled amethyst

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Yellow Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Orbicular granite (likely Rapakivi-type granite)

Granite, chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Petrified Wood

Silicified Wood (SiO2)

Weathered vuggy quartz-rich rock (probable silicified limestone or quartz breccia)

Microcrystalline quartz (SiO₂) with calcite (CaCO₃), iron oxides, and minor clay minerals

Sandstone Pebble (River Rock)

Sandstone (Quartz-rich sedimentary rock with iron oxide staining)