Mineral Based Human Made Alloy

Basalt

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Citrine Quartz

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Schist

Mica Schist (primarily Muscovite and Quartz)

Tree Agate

Silicon Dioxide (SiO2) with Chlorite inclusions

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Biotite Schist

Biotite Schist

K2 Azurite Granite / K2 Stone

Granite (igneous rock) with Azurite inclusions (mineral)

Chert (also known as Flint or Common Chalcedony)

Cryptocrystalline Silica (SiO2)

Desert Varnish (on Sandstone)

Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)

Shale

Clastic sedimentary rock (primarily clay and silt minerals)

Granite Cobble

Felsic intrusive igneous rock (composition: SiO₂ with KAlSi₃O₈, NaAlSi₃O₈, and CaAl₂Si₂O₈)

Heat-Treated Amethyst (Commercial Citrine)

Silicon Dioxide (SiO2) - Macro-crystalline Quartz

Galena

Galena (Lead Sulfide), PbS

Mica Schist

Mica Schist (Quartz-Biotit-Muscovite Schist)

Banded Black Onyx (Chalcedony)

Silicon Dioxide (SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Micaceous Schist

Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)

Quartz with Mica (Schist/Pegmatite fragment)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

River Cobble (likely Basalt or Rhyolite)

Extrusive Igneous Rock (Mafic or Intermediate)

Basalt (Vesicular)

Basalt (Mafic Extrusive Igneous Rock)

Ferruginous Breccia

Breccia with Iron-rich (Hematite/Goethite) Matrix

Ferruginous Sandstone

Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)

Granodiorite

Granodiorite (Quartz-Feldspar-Biotite Plutonic Rock)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Mica Schist

Mica Schist (predominantly composed of Muscovite or Biotite silicates)

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Sandstone (Muddy/Silty Variety)

Arenite with high silt/clay content (clastic sedimentary rock)

Mica Schist with Pyrite

Muscovite/Biotite Schist with Iron Sulfide (FeS2)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Quartzite (Milky Quartz Cobble)

Silicon Dioxide (SiO2)

Basalt River Pebble

Basalt (Aphanitic Mafic Volcanic Rock)

Glauconitic Sandstone (Greensand pebble)

Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)

Diamond (in jewelry)

Carbon (C)

Cat's Eye Moonstone (Simulated/Synthetic or natural Cat's Eye Quartz/Glass)

There is no single scientific name. The appearance suggests either: Moonstone (feldspar group), Cat's Eye Quartz (SiO2), Apatite (Ca5(PO4)3(F,Cl,OH)), or most likely a synthetic material such as Fiber Optic Glass or 'Opalite' (a type of glass).

Gneiss (with Quartz and Biotite Mica)

Gneiss

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Basalt with Quartz/Epidote Vein

Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)