Platinum
Platinum (symbol: Pt, atomic number: 78) is a dense, malleable, ductile, highly unreactive, whitish Metal belonging to the Platinum Group Metals (PGMs). It is a Transition Metal known for its exceptional resistance to corrosion and high melting point.
Properties & Characteristics
- Physical: Silvery-white, highly lustrous, dense (21.45 g/cm³).
- Chemical: Noble metal; resistant to acids (dissolved only by aqua regia or hot sulfuric acid with an oxidizing agent).
- Isotopes: Six naturally occurring isotopes; all are stable.
Historical Context & Perception
The valuation of platinum has undergone a dramatic reversal, shifting from a nuisance impurity to a coveted precious metal.
- Early Discovery: First encountered by Spanish colonizers in the New World (specifically Colombia) in the 16th century.
- Initial Rejection: Referred to as “platina” (little silver), it was initially dismissed as a debasement agent for Silver because it could not be smelted with available early techniques due to its high melting point.
- Industrial Challenges: 18th-century chemists (e.g., Antonio de Ulloa, Charles Wood) struggled to isolate pure platinum. It was often used as ballast in ship holds or dumped in rivers to avoid customs duties on silver.
- Modern Valuation: By the late 18th and 19th centuries, advances in metallurgy allowed for purification. Its rarity and stability elevated its status, eventually surpassing Gold in value in many markets.
- Detailed Analysis: See Platinum: From “Little Silver” to Valued Element—A Historical Overview for a comprehensive breakdown of this historical shift, including the narrative from The History Guy.
Applications
- Jewelry: High-end rings, watches (valued for durability and hypoallergenic properties).
- Catalysis: Catalytic converters in automobiles, chemical manufacturing, and Petroleum refining.
- Electronics: Multi-layer ceramic capacitors, hard disk drive platters.
- Medicine: Cisplatin and related compounds in Chemotherapy; pacemaker electrodes.
- Investment: Physical bars and coins as a store of value.
See Also
- Gold
- Palladium
- Rhodium
- Periodic Table