What is platinum?

When you think of jewelry, silver, gold and platinum are probably among the first metals that come to mind. But did you know that platinum is classified as one of the precious metals due to its rarity and high economic value?

Discover the fascinating history, unique properties and many uses of this exceptional metal, now considered one of the most prestigious materials in fine jewelry and high jewelry.

DISCOVERY OF PLATINUM

Platinum, a precious metal highly prized in jewelry making, has a rich history stretching back thousands of years.

Its use can be traced back to Ancient Egypt, around 700 BC, where small quantities of the metal were incorporated into precious objects. Traces of platinum have notably been identified on a coffin discovered in a tomb in Thebes. Unlike other ancient civilizations such as Greece, Rome and China, however, platinum does not appear to have played a significant role in their respective cultures.

On the other side of the world, in South America, between present-day Colombia and Ecuador, funerary objects containing platinum and dating back approximately 2,000 years have also been unearthed.

These discoveries provide fascinating evidence that platinum was used independently in different parts of the world throughout history, long before its properties were fully understood.

A Sample of Platinum: Who Discovered It?

Because the precise origins of platinum's discovery remain uncertain, the real question is who first recognized the unique nature of this metal and when.

An Italian scholar named Julius Caesar Scaliger is considered one of the earliest Europeans to have described it. In 1557, he wrote about a metal from Central America that could not be melted, although he did not give it a lasting name. His observations attracted little attention at the time, and platinum was later rediscovered independently.

In the 18th century, following the Spanish colonization of South America, greater attention was paid to this unusual metal. It resembled silver in appearance while retaining its own distinctive brilliance.

In 1735, Antonio de Ulloa studied platinum in Peru and later shared his findings with the Royal Society of London. From this period onward, platinum gradually began to be recognized by European scientists as a distinct metal and chemical element in its own right.

Why Is It Called “Platinum”?

The word “platinum” comes from the Spanish platina, a diminutive of plata, meaning “silver” — literally, “little silver.”

Spanish conquistadors encountered the metal mixed with deposits of gold and silver in Colombia. At first, they regarded it as an undesirable impurity of little value, which explains the somewhat dismissive origin of its name.

Only later, as its exceptional properties, rarity and durability became better understood, did platinum gain recognition as a precious metal. Today, it is one of the most prestigious and sought-after metals used in fine jewelry, particularly for engagement rings, wedding bands and other precious creations.

Platinum in Practice

Among metals, platinum stands out as one of the least reactive. Its remarkable resistance to corrosion, even at high temperatures, makes it an exceptionally stable and valuable metal. Platinum is generally found in its native state, meaning it occurs naturally without being chemically combined with other elements. It is mainly found in certain nickel and copper ores, as well as in native deposits, with South Africa accounting for around 80% of global platinum production.

Platinum also occurs naturally in the alluvial sands of various rivers. Pre-Columbian peoples of South America were among the first civilizations known to have used this precious metal to create decorative and handcrafted objects.

Today, platinum has a wide range of applications, including catalytic converters, laboratory equipment, electrical contacts and electrodes, precision thermometers, dental instruments and, of course, fine jewelry.

Because of its exceptional resistance to corrosion, the metallic platinum used in jewelry is not associated with any known adverse health effects when worn as a piece of jewelry. Health concerns related to soluble platinum salts apply exclusively to specific situations involving prolonged industrial exposure and are unrelated to the everyday wearing of platinum jewelry.

Certain platinum-based compounds, such as cisplatin and oxaliplatin, are also used in medicine as chemotherapy treatments for certain cancers. However, these belong to an entirely different, pharmaceutical application of platinum compounds.

The History of Platinum Across Civilizations

Archaeologists have identified traces of platinum in gold artifacts from Egyptian burials dating back to around 1200 BC. Pre-Columbian peoples living near present-day Esmeraldas in Ecuador also used this metal to create objects made from alloys of gold and platinum.

They employed a sintering process that involved combining gold and platinum powders. The resulting alloy was sufficiently malleable to be shaped using relatively simple tools.

Interestingly, the platinum found in these objects was not pure. It was a naturally occurring mixture that also contained small amounts of rhodium, palladium and iridium, metals that are commonly found alongside platinum in nature.

The first known reference to platinum in European culture appeared in the writings of Italian humanist Julius Caesar Scaliger in 1557. He described an unknown metallic substance discovered between the Darién region and Mexico that no Spanish fire or technique had yet been able to melt.

Antonio de Ulloa is now widely recognized as the first European to formally study and describe platinum in 1735. In 1748, he founded Spain's first mineralogy laboratory and undertook the first truly systematic study of the metal.

A few years later, in 1752, Swedish chemist Henrik Scheffer published his own detailed study of platinum, making an important contribution to its scientific recognition throughout Europe.

Properties of Platinum

Physical Properties of Platinum

Pure platinum is a lustrous, ductile and malleable metal.
With its characteristic silvery-white appearance, platinum is more ductile than silver, gold or copper, making it one of the most ductile pure metals known.
Platinum is distinguished by its excellent corrosion resistance, high-temperature stability and stable electrical properties.
At approximately 500°C, platinum can undergo slight oxidation, although the resulting oxide can generally be removed easily through heating.
Platinum reacts vigorously with fluorine at around 500°C, resulting in the formation of platinum tetrafluoride.
Under certain conditions, platinum can also react with chlorine, bromine, iodine and sulfur.
Platinum is insoluble in hydrochloric acid alone but can be dissolved in hot nitrohydrochloric acid, commonly known as heated aqua regia.

Chemical Properties of Platinum

The most common oxidation states of platinum are +2 and +4.
The +1 and +3 oxidation states are observed much less frequently.
Although elemental platinum generally has low chemical reactivity, it dissolves in heated aqua regia, producing chloroplatinic acid.
Platinum exhibits soft-acid characteristics and has a strong affinity for sulfur, particularly in compounds involving sulfur-containing ligands such as dimethyl sulfoxide.

How Is Platinum Produced?

Platinum production, like that of other platinum-group metals, generally occurs as a by-product of nickel and copper mining and processing.

During the electrolytic refining of copper, precious metals such as silver, gold and platinum-group metals settle at the bottom of the electrolytic cell as anode slime. This material then serves as the starting point for the subsequent extraction and separation of these valuable metals.

When native platinum is found in alluvial deposits or other ores, several methods can be used to separate it from impurities. Because platinum has a much higher density than many unwanted materials, lighter particles can be separated and removed using appropriate gravity-based processes.

Heavier impurities such as nickel and iron can then be removed using magnetic separation techniques. Since platinum also has an exceptionally high melting point, certain impurities can be melted or removed through high-temperature processing without compromising the platinum itself.

Platinum's chemical resistance also plays an important role in its purification. Because it resists hydrochloric and sulfuric acids when these acids are used separately, some unwanted substances can be attacked and dissolved while leaving the platinum largely unaffected. The remaining platinum can then be recovered after the mixture has been processed.

One particularly effective method for refining crude platinum mixed with gold and other platinum-group metals (PGMs) involves treatment with heated aqua regia. Platinum, palladium and gold dissolve during this process, while osmium, iridium, ruthenium and rhodium remain largely unaffected and can subsequently be separated.

Uses of Platinum

Catalyst: Platinum plays a major role as a catalyst in numerous chemical reactions, a use that dates back to the early 19th century. It is particularly important in the petroleum industry, especially for naphtha reforming. Its best-known application, however, is probably in automotive catalytic converters, where it helps promote the complete combustion of unburned hydrocarbons before they are released into the atmosphere.
Investment and fine jewelry: As a precious, durable material, platinum is highly valued in fine jewelry, where it is often used in alloys containing 90% to 95% platinum, taking advantage of its remarkable chemical stability. It is also sought after for its prestige and intrinsic value as a precious investment metal. In luxury watchmaking, several renowned maisons use platinum to create exceptional and exclusive timepieces.
Historical scientific standard: Between 1889 and 1960, the metre was defined by the length of a platinum-iridium alloy bar (90:10) known as the International Prototype of the Metre. Platinum resistance thermometers are also among the reference instruments used to define the International Temperature Scale of 1990 (ITS-90).
Other industrial applications: Platinum is also used as an alloying element in the manufacture of fine wires, corrosion-resistant laboratory vessels, medical instruments, dental prostheses, electrical contacts and thermocouples. When alloyed with cobalt, it can also be used to produce particularly powerful permanent magnets.

How to Wear and Choose Platinum Jewelry

Platinum is an excellent choice for an engagement ring, a wedding band, a bracelet or earrings.

Its naturally silvery-white color is durable and does not require a surface treatment, unlike white gold, which is often rhodium-plated. This makes platinum a particularly attractive choice for jewelry designed to be worn every day for many years, especially engagement rings and wedding bands.

Platinum is also denser than gold, giving platinum jewelry a distinctive sense of weight and quality that is highly appreciated by jewelry enthusiasts. It is exceptionally durable, although its surface can develop fine marks over time. Rather than losing significant amounts of metal, these marks gradually create the characteristic “platinum patina”, a soft, distinctive finish that is particularly appreciated by some lovers of vintage and timeless jewelry.

FAQ — Frequently Asked Questions About Platinum

How can I tell if my ring is made of genuine platinum?
Authentic platinum jewelry generally bears a hallmark indicating its purity. Look for marks such as “Platinum,” “PLAT” or “PT,” often accompanied by a number such as “950” or “999.” These numbers indicate the platinum content of the alloy, with 999 representing an exceptionally high level of purity.

Does platinum stick to a magnet?
No. Pure gold, silver and platinum are not magnetic. If a piece of jewelry is strongly attracted to a magnet, this may indicate the presence of other magnetic metals in the alloy rather than pure precious metal. However, a magnet test alone is not sufficient to authenticate platinum jewelry.

Does platinum wear down over time?
Platinum offers exceptional durability. Unlike some precious metals that can gradually lose material through repeated friction and scratching, platinum tends to displace rather than shed metal when scratched. As a result, it wears away very slowly, making it an excellent choice for everyday jewelry such as engagement rings and wedding bands.

What is the difference between white gold and platinum?
White gold is an alloy of gold and white-colored metals and is commonly coated with a thin layer of rhodium to achieve a brighter white appearance. This rhodium plating can gradually wear away and may require periodic maintenance. Platinum, on the other hand, is naturally silvery-white and does not require rhodium plating to maintain its color.

Is platinum hypoallergenic?
Platinum is generally considered an excellent choice for sensitive skin, particularly because jewelry-grade platinum is often highly pure, commonly around 950 parts per thousand (95%), and the metal itself has very low chemical reactivity. However, individual reactions can depend on the other metals present in the alloy.

Why is platinum so expensive?
The high price of platinum is explained by several factors, including its extreme rarity, the complexity of its extraction and refining processes, and strong demand from both industrial sectors and the fine jewelry industry. Platinum is considerably rarer than gold in the Earth's crust, further contributing to its prestige and value.

How should I care for platinum jewelry?
Platinum does not require any special surface treatment to preserve its natural color. Regular cleaning with lukewarm soapy water and a soft-bristled brush is generally sufficient to maintain its appearance. The natural patina that develops over time can also be restored to a brighter finish through professional polishing if desired.