Platinum: Why Does This Lustrous Metal Stand Out?

Platinum is highly prized for its rarity, durability, and adaptability. Its limited supply enhances its exclusivity and worth, while its resistance to wear and ability to endure harsh environments make it perfect for diverse industrial applications.

Expressions such as "platinum status" and "going platinum" suggest that this precious metal reigns supreme. But how does platinum truly measure up, especially when compared to its rival, gold?

Let’s delve deeper into this gleaming metal and explore how it stacks up against its golden rival.

What Is Platinum?

Platinum, a chemical element symbolized as Pt and bearing the atomic number 78, is a rare and radiant metal.

As a pure substance, platinum is defined by its distinct atomic structure, showcasing extraordinary properties: immense density, unparalleled resistance to corrosion, and an impressively high melting point. These qualities make it invaluable across a wide range of industries.

Though platinum is relatively rare, it is naturally found alongside other platinum-group metals such as palladium and rhodium. Major sources of platinum include prominent platinum-producing regions like South Africa, Russia, and Canada, as well as parts of North and South America.

South Africa, especially the Bushveld Complex area, is the primary source of native platinum, housing one of the planet's largest known platinum reserves. This region plays a crucial role in meeting global platinum demand.

Tracing back to pre-Columbian societies in South America, platinum gets its name from the Spanish word "platina," meaning "little silver."

Uncovering Platinum

William Hyde Wollaston and Smithson Tennant, prominent chemists from the late 18th and early 19th centuries, made notable contributions to platinum chemistry, particularly in studying its reactions with specific acids.

Wollaston is celebrated for developing a technique to dissolve platinum using aqua regia, a powerful blend of nitric and hydrochloric acids. This was groundbreaking, as platinum's resistance to chemical reactions made it challenging to work with. This innovation paved the way for advanced analysis and the creation of malleable platinum.

Tennant, working alongside Wollaston, carried out in-depth studies on platinum group metals, particularly focusing on their reactions with acids.

Together, they examined numerous platinum ores and residues, leading to the identification and characterization of several new elements in the platinum group, including iridium and osmium. These breakthroughs were achieved through acid reactions and detailed chemical analysis.

Platinum vs. Gold

Platinum, a naturally occurring chemical element, is approximately 30 times scarcer than gold, as stated by Jenny Luker, president of Platinum Guild International USA (PGI), a marketing body for the platinum jewelry sector.

"If all the platinum ever extracted were melted and poured into an Olympic-sized pool, it would barely cover your ankles. In contrast, gold would fill three such pools," she explains via email. Indeed, platinum is the rarest among the widely recognized precious metals.

Visual Characteristics

Platinum boasts a silvery-white, lustrous appearance. Its resemblance to white gold often causes confusion for those unfamiliar with the metals.

"White gold is essentially yellow gold blended with other metals and coated with rhodium to achieve a whiter look — a temporary mask that eventually reveals a yellowish hue," Luker explains. "Platinum, however, retains its natural white hue indefinitely."

This isn’t to say platinum remains entirely unchanged. "Upon close inspection of a well-worn platinum jewelry piece, you’ll observe a soft, satin-like sheen on its surface, a result of wear over time. This texture shift is referred to as 'patina,'" Luker notes. Interestingly, many platinum enthusiasts cherish this natural aging effect.

Durability

Platinum surpasses gold in durability, making it a preferred choice for engagement rings. (Gold prongs are more prone to breaking compared to platinum ones.)

These superior qualities have historically made platinum more expensive than gold, though Luker points out that the price gap has narrowed significantly.

"Currently, platinum costs less per ounce than gold. However, due to its higher purity (typically 95 percent platinum compared to 58.5 percent gold in 14-karat gold jewelry) and greater density, platinum jewelry remains slightly more expensive than its gold counterparts," she explains. (As of October 2, 2023, platinum was priced at $894.05 per ounce, while gold stood at $1,837 per ounce.)

Mining the Precious Metal

Platinum is primarily mined in South Africa, with additional sources in Russia, Zimbabwe, the United States, and Canada. The extraction process employs various mining techniques, each tailored to specific geological conditions and deposit types.

Underground Mining

Several underground mining techniques exist. In shaft mining, vertical shafts are dug to reach deep ore deposits. Elevators and hoists are utilized to move workers and equipment into the underground mine.

Decline or adit mining involves creating horizontal tunnels, referred to as declines or adits, into the ore body from the side of a hill or mountain. This approach provides access to underground deposits without requiring a vertical shaft.

Room and pillar mining is a technique where the ore body is segmented into chambers or rooms, with pillars of ore left intact to support the roof. This method is ideal for deposits with stable geological conditions.

Open-pit Mining

This mining approach involves digging extensive, deep pits to reach ore deposits located near the surface. It is suitable for shallow deposits but can cause substantial environmental impact due to the large-scale excavation required.

Open-pit mining, though efficient for shallow platinum deposits, often leads to considerable environmental disruption because of the vast areas excavated. As a result, it is less preferred in modern mining operations.

Alluvial Mining

Alluvial mining focuses on extracting precious minerals from sedimentary deposits, commonly found in riverbeds, floodplains, or areas where water has transported eroded materials.

The process starts with natural erosion, where geological forces free minerals from their original locations. Water transports these materials, depositing them as its flow slows. Miners then extract these sediments manually or mechanically, targeting valuable minerals such as gold, diamonds, or platinum.

Methods like panning and gravity separation are employed to isolate valuable minerals from less desirable materials. Once concentrated, additional steps such as refining or smelting are undertaken to produce the final product.

This approach is commonly applied to minerals that are easily transportable and varies depending on the specific mineral being targeted and the scale of the operation.

Heap Leaching

This technique is utilized to recover valuable metals, typically from low-grade ores. In this method, the ore is crushed and arranged into heaps or piles. A leaching solution, often containing chemicals such as cyanide, is then applied to the heap. Over time, the solution filters through, dissolving the desired metals.

The dissolved metals are subsequently collected and processed further to isolate the target metal, while the leftover waste is disposed of in an environmentally safe manner. Heap leaching is an economical method for specific types of ore deposits.

In-situ Recovery (ISR)

In-situ recovery (ISR), also referred to as in-situ leaching or solution mining, is a technique for extracting valuable minerals from ore deposits without physically excavating the ore. Instead, a leaching solution is injected directly into the underground ore body.

The solution dissolves the desired minerals, and the enriched liquid is then pumped to the surface for further processing. ISR is regarded as environmentally friendly, as it reduces surface disruption and waste production, making it an ideal choice for specific deposit types.

Common Platinum Uses

While platinum's durability and aesthetic appeal have made it a top choice for jewelers and buyers, this silvery-white metal boasts a wide range of applications, some of which may come as a surprise.

Catalysis

Platinum serves as a catalyst in the production of chemicals such as silicone, nitric acid, and benzene. Notably, the six platinum group metals (iridium, palladium, platinum, rhodium, ruthenium, and osmium) are renowned for their exceptional catalytic abilities (meaning these metals accelerate chemical reactions between substances without altering their physical properties).

Auto Parts

In the automotive sector, platinum plays a crucial role in catalytic converters. In fact, approximately half of platinum's demand stems from its use in catalytic converters for vehicles like cars, trucks, and buses.

These devices transform harmful exhaust emissions, including carbon monoxide (CO), nitrogen oxides (NOx), and unburned hydrocarbons, into less toxic substances such as carbon dioxide (CO2), nitrogen, and water vapor.

Jewelry

Platinum and platinum wire are highly valued in jewelry creation for numerous reasons. Their natural, silvery-white luster offers a classic and sophisticated look that pairs beautifully with various gemstones and designs. Platinum's remarkable durability ensures that jewelry pieces remain pristine over time, making it an ideal choice for family heirlooms.

Platinum wire — slender, flexible strands crafted from platinum — boasts a malleability that enables detailed and delicate artistry. Additionally, platinum's hypoallergenic nature makes it a safe option for individuals with sensitive skin.

Healthcare

In the medical field, platinum compounds are used in certain chemotherapy medications, as well as in pacemakers and dental fillings. The electronics industry also finds diverse applications for platinum, such as in computer hard drives.

Cisplatin is a platinum-based compound utilized in chemotherapy to combat various cancers. It functions by disrupting the DNA of cancer cells, halting their replication and growth. Other platinum-derived chemotherapy drugs include carboplatin and oxaliplatin.

Military Applications

From a military perspective, platinum has long been prized for its durability, which extends far beyond mere scratch resistance. The metal performs exceptionally well under extreme heat, maintains stable electrical properties, and resists chemical corrosion effectively.

For instance, platinum-based coatings on jet engine blades safeguard them in environments where temperatures can soar to 2,000 degrees Celsius (3,632 degrees Fahrenheit).

"Platinum was a crucial strategic defense metal during World War II and was restricted from jewelry use at the time," Luker explains. Even today, platinum remains vital to economic and defense initiatives, earning its place as one of the 35 minerals considered essential to U.S. national security and the economy.

Given its impressive attributes, platinum's esteemed reputation and high value are undoubtedly justified.