Descriptive Mineralogy Native Elements Pure elements that occur

Classification of the Minerals • Non-Silicates – Native Elements – Halides – Sulfides –

Native Elements: Metals • Fe, Co, Ni: Meteorites • Platinum Group: (Ru, Rh, Pd,

Native Iron: Meteorites Widmanstätten Pattern

Platinum Group Metals Ru, Rh, Pd, Os, Ir, Pt • Strongly siderophile elements •

Native Elements: Cu, Ag, Au • Cu and Ag: Supergene Enrichment – Oxidation of

Native Elements: non metals • Carbon: – Graphite: Metamorphic Rocks – Diamond: Kimberlites •

Native Elements: Carbon • Graphite (Low Pressure) – Metamorphosed Organic-rich sediments • Diamond (High

Native Elements: Sulfur • Fumaroles (Volcanic hydrothermal vents) – Oxidation of H 2 S

In the caps of salt domes, gypsum (Ca. SO 4 2 H 2 O)

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Descriptive Mineralogy Native Elements: Pure elements that occur as minerals

Classification of the Minerals • Non-Silicates – Native Elements – Halides – Sulfides – Oxides – Hydroxides – Carbonates – Sulfates – Phosphates • Silicates – Orthosilicates – Sorosilicates – Cyclosilicates – Chain Silicates – Layer Silicates – Tektosilicates

Native Elements

Native Elements: Metals • Fe, Co, Ni: Meteorites • Platinum Group: (Ru, Rh, Pd, Os, Ir, Pt): Mafic Igneous Rocks • Coinage metals: Cu, Ag, Au – Cu, Ag: Supergene Enrichments (Sulfide Oxidation) – Au: Low Temperature Hydrothermal, Placer

Native Iron: Meteorites

Native Iron: Meteorites Widmanstätten Pattern

Iron-Nickel Phase Diagram

Platinum Group Metals Ru, Rh, Pd, Os, Ir, Pt • Strongly siderophile elements • Enriched in Fe meteorites • Found in layered mafic intrusions – Bushvelt Complex (South Africa) – Stillwater Complex (Montana) – Skaergaard Complex (Greenland)

Bushvelt: Layered Gabbroic Intrusion

Skaergaard: Layered Gabbroic Intrusion

Native Elements: Cu, Ag, Au • Cu and Ag: Supergene Enrichment – Oxidation of Cu, Ag sulfides in unsaturated zone – Precipitation of metal, oxides and carbonates at water table • Ag and Au: hydrothermal – Native metals and tellurides • Au: placer – oxidized hydrothermal

Supergene Copper

Hydrothermal Silver

Hydrothermal Gold

Native Elements: non metals • Carbon: – Graphite: Metamorphic Rocks – Diamond: Kimberlites • Sulfur (+Se): – Salt Domes (Sulfate reduction), – Volcanos (H 2 S oxidation) • Tellurium (Te) Telluride oxidation

Native Elements: Carbon • Graphite (Low Pressure) – Metamorphosed Organic-rich sediments • Diamond (High Pressure >100 km) – Kimberlites – Placers from kimberlites

Native Elements: Diamond

Kimberley Mine 1875

Native Elements: Sulfur • Fumaroles (Volcanic hydrothermal vents) – Oxidation of H 2 S • Salt dome cap rocks – Sulfate reduction by petroleum

Fumarole Sulfur: Nysseros

In the caps of salt domes, gypsum (Ca. SO 4 2 H 2 O) is reduced to native sulfur

Native Elements