Learn how different platinum alloys impact your jewelry-making process and find the best material for any job.
Platinum continues to maintain its high reputation in the jewelry industry, and for good reason — its durability, natural white color, and superior wear resistance make it an ideal choice for customers seeking pieces that can withstand everyday wear and have future heirloom characteristics. This precious metal not only enhances the beauty of a piece but also helps build trust with your customers thanks to its lasting quality.
However, bench jewelers must know that not all platinum is the same. The specific alloy you choose can affect how easy it is to work with and how long a piece will keep its original strength and finish.
Whether you’re new to working with platinum or have years of experience with this revered material, understanding the differences between platinum alloys is key. In this guide, we’ll walk you through the main platinum alloys used in various jewelry manufacturing processes, explaining their unique traits and how to choose the best one for your needs.
Why Platinum Alloys Matter
When working with platinum, the alloy you choose is more than just a material — it's a key factor in the quality and outcome of your work. Different platinum alloys offer varying levels of workability, durability, and finish, so it's essential to match the alloy to the task at hand. Consider your specific needs: Do you require an alloy that's easy to cast, or one that's better suited for die striking? The bottom line is that the results you achieve will depend on making the right choice.
Try keeping these three points in mind when it comes to selecting a platinum alloy.
Workability: How easily can the alloy be shaped, cast, or machined?
Your Needs: What is the type of jewelry you’re creating and the manufacturing processes you’ll use to fit your customer’s lifestyle or request?
Results: Will the piece's final appearance, strength, and longevity meet your and your customer’s expectations?
Platinum/Ruthenium (Pt950/Ru)
Ruthenium Pt950/Ru is a versatile, all-purpose platinum alloy for the jewelry industry and the most widely used in the United States.
Great for: Machining and fabrication
Suitable for: Casting and die striking
Benefits and Features
- Excellent balance of strength, workability, and resistance to daily wear
Ruthenium Pt950/Ru is a reliable choice for jewelers looking for an all-around performer. It’s durable, easy to work with, and provides a bright, white finish that holds up over time — timeless qualities that will give your customers a finished piece they can cherish for generations to come.
Platinum/Cobalt (Pt950/Co)
Cobalt Pt950/Co is another popular alloy valued for its casting capabilities. Its durability lends itself well to intricate designs or detailed work. However, this alloy does have a higher chance of oxidizing due to its content.
Great for: Casting
Suitable for: Machining, fabrication, and die striking
Benefits and Features
- Reduces porosity and shrinkage for cleaner, more precise results
- Ideal for detailed designs
- May require extra polishing from oxidation but is easily managed
Cobalt Pt950/Co is an excellent choice for jewelers seeking a durable and effective alloy for casting and intricate designs. This harder alloy combines strength with smooth casting, though it may need additional polishing to address oxidation. Overall, this alloy is a reliable and valuable option for creating high-quality platinum jewelry in the shop or at the bench.
Platinum/Iridium (Pt900) or Platinum/Iridium (Pt950)
When choosing between Platinum/Iridium (Pt900) and Platinum/Iridium (Pt950), it's essential to understand their differences and how they affect your work. The main difference is alloy content: Pt900 contains 10% iridium while Pt950 contains 5% iridium. This slight variation can severely impact casting and final results when it comes to jewelry, and making the right choice can be crucial.
Features and Benefits of Platinum/Iridium (Pt900)
Excellent Reflectivity
Using this alloy is ideal for diamond and gemstone settings where high shine is important.
Durable
This alloy offers good resistance to corrosion and abrasion and keeps that revered platinum quality for any piece.
Hypoallergenic
With a high platinum content, it's suitable for those with sensitive skin.
Keep in Mind
Platinum/Iridium (Pt900) is a softer alloy that needs careful handling. However, it's preferred for hand-fabricated designs because the metal hardens during the fabrication process, making it ideal for intricate work.
Why Shouldn’t I Use Platinum/Iridium (Pt950)?
While Platinum/Iridium (Pt950) is not void of advantages, it may not be the best choice for all jewelry-making applications. Here’s why Pt950 might not be suitable:
Too Soft for Casting
Pt950’s high platinum content makes it softer and less ideal for casting. Its softness can lead to issues, such as distortion and poor performance in the mold. This can affect the final shape and integrity of the piece, making it less reliable for intricate designs.
Less Secure Setting
While Pt950 is easier to work with for setting stones, its softness can compromise the security of your gems. It can easily distort prongs and shanks, which may lead to loosely set or lost stones over time. This reduces the long-term durability and reliability of your customer’s platinum jewelry.
Susceptibility to Wear and Tear
The softness of Pt950 makes it more prone to scratches and deformation with everyday wear. This can affect the longevity and appearance of the piece, making it less suitable for items that will be worn frequently such as bridal jewelry.
For pieces that need to withstand everyday use, considering an alloy with greater hardness and resilience may be a better choice to ensure long-term satisfaction for your customers, especially those who are looking to invest in future heirloom quality.
Responsibly Mined Platinum
Looking for an alloy choice that aligns closer to your business’s and your customer’s needs? Made with responsibly mined platinum from Anglo American. Platinum supplied by Anglo American to Stuller has been sourced in compliance with Anglo American’s Responsible Sourcing Standard and the London Platinum and Palladium Market (LPPM) Responsible Platinum/Palladium Guidance.
Inoveo Platinum
By choosing Inoveo Platinum Grain from Stuller, you can confidently offer your customers a product that supports their values while delivering the exceptional quality they demand. Stuller’s commitment to ethical sourcing ensures that you can provide jewelry that aligns with modern standards of responsibility and excellence. As consumers increasingly value responsibly sourced materials and ethical practices, this platinum is a premium choice that meets their expectations for durability and responsible sourcing.
To shop Inoveo Platinum Grain, click here or call 800-877-7777, ext. 4300, to speak with our Tools Tech Team for any purchasing questions.
Bringing It All Together
Selecting the right platinum alloy is essential for achieving outstanding results in your jewelry projects. Each alloy — from the versatile Ruthenium Pt950/Ru to the durable Cobalt Pt950/Co and the distinctive Iridium Pt900 — has benefits tailored to specific needs.
At Stuller, we’re dedicated to supporting you with top-notch materials and expert guidance. By partnering with global leaders in the industry such as Platinum Guild International (PGI), we provide the resources and insights you need to make the best choices and deliver high-quality jewelry that lasts.