Platinum is a dense, silvery-white precious metal highly valued for its natural brilliance and durability, particularly in fine jewelry. When people ask if platinum tarnishes, they are typically concerned about the dark, chemical discoloration seen on metals like silver. The direct answer is that platinum does not tarnish in this traditional chemical sense, making it an exceptional choice for long-term wear. Its inherent stability means it retains its natural white color indefinitely without the need for plating.
The Direct Answer: Tarnish Versus Patina
Tarnish is a chemical process where a metal reacts with air, moisture, or sulfur compounds, creating a surface layer of corrosion that appears as a darkened or discolored film. Metals like silver and some gold alloys are prone to this form of chemical oxidation, which degrades the metal’s surface appearance. Platinum, however, is chemically inert and does not undergo this discoloration.
The change platinum exhibits over time is known as a patina, which is a physical alteration rather than a chemical one. This patina is a subtle, satiny finish that develops from the microscopic scratches and abrasions of daily wear. Platinum is a relatively soft metal; when scratched, the metal is merely displaced across the surface rather than lost. This displacement causes the polished surface to scatter light differently, resulting in a muted, slightly duller sheen. This characteristic soft, matte look is often prized by collectors for the vintage character it imparts.
The Chemistry Behind Platinum’s Stability
Platinum’s resistance to chemical change is rooted in its classification as a noble metal. This term refers to metals that are highly inert and resistant to corrosion and oxidation in moist air. Platinum is one of the least reactive metals, which accounts for its exceptional stability.
Platinum does not readily react with oxygen, sulfur compounds, or common household chemicals that typically cause tarnish on less stable metals. Its chemical structure prevents it from forming the dark oxide or sulfide layers characteristic of tarnish. This inert nature allows platinum jewelry to maintain its bright white tone without the rhodium plating often required for white gold. Its high stability also means it can withstand exposure to acids and high temperatures.
Maintaining Platinum Jewelry
While platinum does not tarnish chemically, routine care is necessary to remove the oils, dirt, and grime that can accumulate and dull its surface. The simplest at-home method for cleaning platinum jewelry involves soaking the piece in a bowl of warm water mixed with a few drops of mild dish soap. After soaking for about 10 to 15 minutes, a soft-bristled toothbrush can be used to gently scrub away any debris trapped in crevices or around settings.
Rinsing the jewelry thoroughly under running water and drying it with a lint-free cloth will restore its sparkle and remove any superficial buildup. To remove the physical patina of wear and restore the metal’s original mirror-like polish, a professional jeweler must buff and polish the item. Professional polishing smoothes the microscopic ridges and scratches, bringing the metal back to its initial high-gloss finish. Because the metal is only displaced when scratched, professional polishing does not result in a loss of volume, allowing the piece to be restored repeatedly over its lifetime.