Friday, March 27, 2009

Myths about Metals – or “I only buy PURE gold or silver” Pt 5

I’ve been doing a series of blogs this week delving into the facts and myths about Gold, Silver, Copper, Nickel, and “other” metals. So far, I’ve discussed gold, silver and “silvery” metals, Copper, Brass, Bronze, and Zinc. Today, I have saved the rarest (and usually most expensive) for last.

Before I get started tho, just want to mention that my hubby and I celebrated our anniversary early with tickets to the Elton John/Billy Joel Face2Face concert last night. I’m going to age myself here, but the first Elton John 45 I ever bought was Rocket Man. I still have it – and I still love Elton John…but the highlight of the show for me was finally getting to see Billy Joel in concert. Considering all the places and changes life has brought him, the man is still an incredible entertainer. He was warm and witty, and omg, can the man play the piano! Wow!!! Needless to say, it was a WONDERFUL concert and a great way to spend an all too rare evening out with my sweetie!

‘nuf said… back to the jewelry!

Platinum, Palladium, and Rhodium… who can resist the gleam of these incredibly lustrous silvery metals? These three, along with ruthenium, iridium and osmium, form a group of elements referred to as the platinum group metals. These metals are extremely rare (platinum occurs only as .003 parts per billion in the Earth’s crust); platinum and rhodium being the two natively uncombined with any other metals. Rhodium is also more abundantly found within platinum ores, while Palladium can be found as a free metal in platinum metal group deposits as well as alloyed with gold. The extraction process for both of these metals is costly, accounting for their high value in all markets and all uses.

All of these metals have a high resistance to tarnish and platinum and rhodium wear extremely well, making them well suited for fine jewelry finishes. The interesting thing here, is that these metals are actually so strong that they tend to be difficult to shape and form into intricate designs by hand, Rhodium being the least malleable. This probably accounts for rhodium’s use as a plating metal - it is rare to find a piece of jewelry that is solid Rhodium. The use of Palladium in jewelry is relatively new so there is still much research being done to find ways to increase its practicality as a pure metal. Due to its relative softness, it often must be alloyed with another metal like silver or gallium to increase its strength and durability.

Standards for use in Jewelry

Platinum alloys

There are 4 platinum alloys commonly used in the USA.
Pt900/Ir = 900 parts platinum, 100 parts Iridium
Pt950/Ir = 950 parts platinum, 50 parts Iridium
Pt950/Ru = 950 parts platinum, 50 parts Ruthenium
Pt950/Co = 950 parts platinum, 50 parts Cobalt

Jewelry that contains at least 950 parts per thousand of pure platinum may be marked or described as "Platinum"

Jewelry that contains 850, 900 or 950 parts per thousand of pure platinum may be marked "Plat" or "Pt" if a number is used in front of the term to disclose the amount of pure platinum in the mix, such as "850 Plat" or "850 Pt", or "950 Plat" or "950 Pt"

Jewelry that contains at least 950 parts per thousand of platinum group metals, with at least 500 parts per thousand of the total pure platinum, may be marked as platinum as long as the numbers of each metal are disclosed. For instance, "600 Pt. 350 Ir." or 600 Plat. 350 Irid." for 600 parts pure platinum and 350 parts iridium"550Pt. 350Pd. 50Ir." or "550Plat. 350Pall. 50Irid." for 550 parts pure platinum, 350 parts palladium and 50 parts iridum

Rhodium, since it is generally just used as a plating, is usually not alloyed with any other metals, although some jewelry applications do use a Rhodium/Platinum alloy..

950 Palladium Alloys

Standard alloys contain 950 parts of palladium and 50 parts of other metals (this portion of the alloy may vary among suppliers). The most common alloy component in the United States is ruthenium, which, along with palladium, belongs to the platinum group of noble metals. Ruthenium usually accounts for about 4.8 percent of the 5 percent mixture, leaving room for trace metals that improve working, wearing, or casting. The common alloy ingredient used in China, where palladium jewelry is mass produced, is 950 parts palladium and the balance copper.

Anyone who has white gold rings (for example, my engagement/wedding ring set is white gold) should take their rings in at least once or twice a year to have the settings checked and to have the rings shined up. Rhodium is the metal that most jewelers use to flash coat the white gold rings to give them that “brand new” shine. And if you’re like me, and your rings never come off no matter what you’re doing, the Rhodium plating definitely stands up extremely well to the fine scratches that are a part of daily wear and tear.

The cost of these metals in jewelry can be up to 4 times higher than white gold and proportionately higher than sterling silver. Is the cost worth it? That of course is something only you can decide… for most people, these metals just don’t fit into their budgets. But, if you do have the flexibility to consider the cost, keep in mind that while platinum can be 4 times more expensive than gold, it is also 4 times stronger than gold as well. Since these are nearly pure metal alloys as well, allergies are not an issue (except again in those extremely rare cases, because there is a possibility of being allergic to anything). They are extremely tarnish resistant, and will retain their color and luster forever with minimal care.

I managed to find a few examples of each of these lovely metals in some great Etsy shops. I hope you'll take a look at them to see the quality and special look of these great designs. Happy Shopping!

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