Igneous, Sedimentary, Or Metamorphic (Mineral Based)

Mixed Gemstone Bracelet

Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)

River Cobble (Phyllite or Quartzite)

Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)

Zoisite with Ruby

Anyolite (Calcium aluminum hydroxy silicate with Corundum) Ca2Al3(SiO4)3(OH)

Epidote (Unakite variety)

Epidosite (Metasomatic rock containing Ca2(Al,Fe)3(SiO4)3(OH))

Graphite

Graphite (Native Carbon), Formula: C

Citrine

Citrine (Silicon Dioxide - SiO2)

Diamond Drill Core (Greenschist and Quartzite)

Chlorite Schist / Meta-quartzite (Metamorphic Rock Core Sample)

Mica-rich Schist fragment

Mica Schist

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Marble

Metamorphosed Limestone (principally CaCO3)

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Blue Quartzite

Quartzite (silicon dioxide, SiO2)

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

Quartz Pebble

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (Metamorphic Rock)

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

Biotite Mica

K(Mg, Fe)3AlSi3O10(F, OH)2

Quartz with Mica inclusions (likely Schist or Gneiss host)

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

Pebble (likely Sandstone or Granitic Pebble)

Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)

Anthracite Coal

Anthracite (Carbon-based sedimentary-metamorphic rock)

Quartz Vein in Pelite (Metamorphic Rock)

Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Gneiss

Gneiss

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Sandstone

Arenite (SiO2 based)

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Biotite Gneiss

Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)

Epidote

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Gneiss (Pebble)

Gneiss

Biotite Schist

Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Epidote

{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Apatite

Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))

Sandstone

Arenite (SiO2 based)

Zebra Jasper

Silicon Dioxide (SiO2) with various inclusions

Biotite (Mica)

Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)

Gneiss (Granitic Gneiss)

Gneiss (from German Gneis, related to 'spark')