Mineral (Man Modified)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Weathered banded sandstone pebble

Quartz-rich sandstone (predominantly SiO₂)

Quartz

Silicon Dioxide (SiO2)

Gold in Quartz

Gold (Au) in Quartz (SiO2)

Fluorite in Host Rock

Calcium Fluoride (CaF2)

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Quartz Druzy

Silicon Dioxide (SiO2)

Yellow Sapphire

Corundum (Al2O3 with trace amounts of iron)

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Green Fluorite

Calcium Fluoride (CaF2)

Milky Quartz

Silicon dioxide (SiO2)

Bicolor Quartz (Milk Quartz with Slag or Dark Inclusions)

Silicon Dioxide (SiO2) with impurities

Vesicular Basalt

Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)

Quartz Pebble (Water-worn)

Silicon Dioxide (SiO2)

Fluorite (Rainbow Fluorite)

Calcium Fluoride (CaF2)

Banded Iron Formation (BIF)

Banded Iron Formation

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals Mg₃Si₂O₅(OH)₄, with magnetite, olivine, and pyroxene remnants

Likely polished black stone or obsidian

Obsidian (volcanic glass), chiefly SiO₂

Quartz

Silicon Dioxide (SiO2)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Rose Quartz

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

Milk Quartz (Vein Quartz)

Quartz (Silicon Dioxide, SiO2)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Tumbled milky quartz

Quartz (SiO₂), microcrystalline or massive variety

Serpentinite pebble

Serpentinite, composed chiefly of serpentine-group minerals (lizardite, chrysotile, antigorite), with possible magnetite and chlorite

Sandstone (Ferruginous)

Arenite (Fe2O3 rich)

Peacock ore (iridescent chalcopyrite, possibly bornite)

Chalcopyrite, CuFeS₂; the iridescent surface may be natural tarnish or artificial acid treatment. Similar material is bornite, Cu₅FeS₄.

Purple Slate

Foliated slate (Pelitic origin)

Greenstone

Greenschist / Meta-basalt

Yellow Quartz

Silicon Dioxide (SiO2)

Diamond

Carbon (C)

Rutilated Quartz

Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions

Serpentine (likely antigorite-rich serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with dark magnetite/chromite or pyroxene inclusions

Magnetite-rich iron ore (probable magnetite schist)

Magnetite (Fe₃O₄) in a foliated metamorphic matrix, possibly magnetite–biotite schist

Limonite and Goethite encrusted Chert/Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)

Quartz (Orangey-Yellow variety)

Silicon Dioxide (SiO2)

Serpentinite (probable)

Serpentinite, dominated by serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with dark magnetite or chromite and pale carbonate/talc possible

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides

Red Sandstone

Sandstone (lithic arenite / ferruginous sandstone)

Quartz (likely milky/gray variety)

Quartz (SiO₂)