Does Platinum Turn Black? A Comprehensive Guide
The question of whether platinum turns black is a common one, especially for those who own or are considering purchasing platinum jewelry. The short answer is: No, pure platinum does not turn black. However, the reality is more nuanced, involving understanding the properties of platinum, its alloys, and how it interacts with its environment. Let’s dive deep into this precious metal to clarify why it’s unlikely to blacken, and what can cause it to appear different over time.
Understanding Platinum’s Natural Properties
Platinum is a naturally occurring, dense, and durable precious metal. Its inherent color is a beautiful grayish-white, which sets it apart from other white metals like silver and white gold. One of the most appealing aspects of platinum is its resistance to tarnish and corrosion. Unlike silver, which readily reacts with sulfur compounds in the air to form a black tarnish, platinum is largely inert. This means it does not react easily with its surroundings, making it exceptionally durable and low-maintenance.
Platinum’s Patina: A Natural Change
While pure platinum does not turn black, it does develop a patina over time. This patina is not a form of tarnish; instead, it’s a slight change in the surface finish of the metal due to regular wear. The surface of the metal begins to lose its high polish, resulting in a more subtle, matte or satin-like finish. This can sometimes be perceived as a darkening, particularly when comparing a new, highly polished platinum piece to one that has been worn for years. However, this is not the same as the black tarnish seen on silver. Some people appreciate this patina, considering it adds character and a vintage charm to the jewelry. Others prefer to have their platinum re-polished to restore its original luster.
Platinum Alloys and the Potential for Tarnish
It’s crucial to understand that most platinum jewelry isn’t 100% pure platinum. Instead, it’s typically alloyed with other metals to increase its hardness and durability. Common alloying metals include iridium, ruthenium, cobalt, and copper. While these alloys do not typically cause platinum to turn black, some of them, notably copper, are prone to tarnish. When platinum is alloyed with a significant amount of copper, there is a slight chance of discoloration or a very slight darkening from the copper tarnishing. However, this is not common in most high-quality platinum jewelry as the alloy percentage is usually low.
The Blackening Illusion
Often, what people perceive as platinum turning black is actually the result of external factors or dirt accumulation. Everyday substances like soap, lotions, perfumes, and even skin oils can build up on the surface of platinum jewelry, causing it to look duller or darker. Additionally, the fine scratches that accumulate on platinum over time can trap dirt and grime, further contributing to a darkened appearance. This can lead to the misconception that the platinum itself has turned black, when in reality, it’s just a layer of residue that can easily be removed with proper cleaning.
Blackened Platinum: An Intentional Effect
There is also a process to create “blackened platinum” intentionally. This is achieved using a process that involves passing a direct current through platinum foils while they are immersed in a chemical solution, typically containing lead acetate. This procedure creates a controlled black coating on the metal’s surface for a distinctive aesthetic. This is a vastly different process from the natural tarnish seen in other metals and should not be confused with platinum turning black due to everyday wear.
Practical Considerations and Maintenance
Understanding why platinum doesn’t naturally turn black is crucial for proper maintenance of platinum jewelry. Unlike silver, platinum doesn’t require frequent polishing to prevent tarnish. Instead, simple cleaning methods are sufficient to keep it looking its best. Regularly washing your platinum pieces with mild soap and water, and gently scrubbing them with a soft brush can remove build-up and restore their shine. It’s also advisable to avoid harsh chemicals and abrasive cleaners, as these can damage the surface and reduce its luster over time.
Recognizing Authentic Platinum
Genuine platinum jewelry will typically be marked with hallmarks indicating its purity. Look for stamps like “PLAT,” “PT,” or “950,” which signify 95% purity. These markings help ensure that you’re getting a piece made primarily of platinum rather than a plated or alloyed piece that may not have the same properties. The weight and the gray-white hue of the metal are also key characteristics of platinum.
In conclusion, while pure platinum doesn’t turn black, it can develop a patina or appear darker due to external factors like dirt build-up or the tarnishing of alloys like copper. However, with proper care and understanding of the metal’s properties, platinum jewelry will remain a durable and stunning investment for years to come.
Frequently Asked Questions (FAQs) about Platinum
1. What exactly is a platinum patina?
A platinum patina is a change in the surface finish of the metal due to regular wear. It’s often described as a satiny or slightly frosted appearance, rather than the high polish it has when new. This is not a form of tarnish but a natural characteristic of platinum over time.
2. Can household chemicals damage platinum?
Yes, while platinum itself is resistant to corrosion, harsh chemicals in everyday products like cleaning supplies, perfumes, and hairsprays can weaken its structure over time. Additionally, the chlorine in swimming pools can dull platinum’s shine and potentially cause discoloration.
3. What are some common hallmarks used for platinum jewelry?
Platinum jewelry is commonly marked with hallmarks like “PLAT,” “PT,” “950,” or “900 Plat – 100 Irid”. These markings indicate the percentage of pure platinum in the piece, with 950 meaning 95% purity.
4. How do you clean tarnished platinum?
To clean your platinum jewelry, mix mild dish soap with warm water. Add your jewelry to the solution and let it soak for a few minutes. Then, gently scrub it with a soft toothbrush to remove any dirt or buildup. Rinse with clean water and dry with a soft cloth.
5. Will platinum lose its color over time?
No, platinum will not lose its natural white color. It may develop a patina, which changes the surface’s luster, but it will not fade or turn yellow like white gold can. Platinum remains white.
6. Is platinum magnetic?
Pure platinum is not magnetic. However, if platinum is alloyed with metals like cobalt, it may be slightly attracted to a very powerful magnet, as cobalt is magnetic. Alloys with ruthenium, iridium, and palladium will not be magnetic.
7. Does water damage platinum?
No, water does not damage platinum. Platinum is highly durable and less likely to be affected by water compared to other metals, and is non porous.
8. What is the difference between platinum and silver tarnish?
Silver tarnish is a chemical reaction that turns the surface of silver black or dark grey. Platinum’s patina is a change in the surface finish from wear. It does not react chemically and turn black from being exposed to air.
9. Why does my platinum ring turn my finger black?
A black mark on your finger from a ring is usually caused by a chemical reaction between the ring’s metals and your skin, especially due to household detergents or makeup that contain harsh chemicals.
10. What is “blackened platinum”?
“Blackened platinum” is not natural. It’s created by a special process where a direct current is used to coat the metal’s surface in a black layer. This intentional black coating is used for aesthetic purposes.
11. How can you tell if platinum is real?
You can tell if platinum is real by looking for hallmarks like “PLAT,” “PT,” or “950.” The metal will have a grayish-white color, a substantial weight, and will not be magnetic unless mixed with magnetic metals.
12. Can vinegar test platinum?
Vinegar will not damage or react with platinum. Vinegar is a weak acid that does not oxidize platinum. Therefore, it is not an effective way to test for the authenticity of platinum.
13. What are the disadvantages of platinum jewelry?
The main disadvantage of platinum jewelry is that it can lose its high polish and sharp edges relatively quickly. Also, it is a softer metal than many other jewelry metals and will scratch and ding easily.
14. Can platinum be repaired if it’s scratched?
Yes, platinum can be repaired and polished to remove scratches. Many jewelers offer refinishing services that can restore platinum to its original luster.
15. What does oxidized platinum look like?
Oxidized platinum will develop a dull gray appearance. This is caused by a slight reaction with the air, and is technically a patina, which is a natural darkening.