According to “The Knot” — a popular wedding planning website — the most popular month to marry in the US is June. And what’s the most popular metal used for wedding rings? Well, although there are several kinds of precious metals, most couples choose gold or platinum. What’s the difference between the two metals?
Gold and platinum are both dense, malleable, ductile precious metals used in jewelry and industrial applications. Throughout history, gold has always been prized as a symbol of wealth, but platinum is, currently, more valuable than gold. There are many other important differences between these two elements.
Let’s start with the better-known gold. Gold is represented by the symbol Au on the periodic table of elements. Gold is appropriate for some industrial applications because it doesn’t rust or corrode and it conducts both heat and electricity, but gold is valued mostly as jewelry or coins.
As jewelry, gold is typically yellow, white, or red, depending on the alloying elements. White gold doesn’t occur naturally; it gets its silvery hue by being alloyed with white metals such as silver, nickel, manganese, platinum, or palladium. For a shiny finish, white gold is usually coated in rhodium plating that must be replaced periodically to prevent the white gold from reverting back to yellow.
In the industrial world, gold is used primarily as connectors in electronic devices, such as cell phones and computers, because it’s corrosion and tarnish resistant, conducts electricity well, and disperses heat quickly. Various amounts of gold can be found in some large appliances such as microwaves, washing machines, and TVs.
Now let’s look at platinum, represented by the symbol Pt on the periodic table. Platinum is also used to make jewelry and looks similar to white gold, but when compared side by side with white gold you can see that platinum has a more grayish color. Platinum doesn’t fade to yellow like white gold but the finish will dull, so like white gold, platinum jewelry may require some maintenance to keep it shiny.
Platinum is more dense than gold, and by law jewelry that is labeled “platinum” must be at least 95% pure platinum, so a platinum ring will weigh, and therefore cost, more that a gold ring of the same size. (14k gold is only 58.5% gold and 18k gold is 75% gold). Platinum is stronger and more durable than gold. However, a distinct advantage of platinum is that it’s hypoallergenic, whereas some people will have an allergic reaction to white gold due to the nickel alloy it contains. Palladium, one of the Platinum Group Metals, may be an even better choice than platinum because it has similar characteristics as platinum at a lesser price.
Platinum and palladium may be good choices for jewelry, but most of these metals are produced for industrial purposes such as catalytic converters and numerous electronic components. Platinum can also be used in diesel engines, and petroleum and chemical refining catalysts. Palladium is used to make metallic glass, polymer membranes, coatings, plastics, textiles, and fuel cells. Palladium nanoparticles are finding applications as potential drug delivery mechanisms.
Market analysts project continued volatility in the price of gold while the price of platinum is expected to rise due to dwindling supply and increasing demand. For businesses that buy and recycle precious metals such as jewelry stores, refineries, and pawn shops, failing to distinguish between white gold, platinum, and palladium or to detect even a small variation in the composition of one of these precious metals can be an expensive mistake.
Many businesses are now turning to X-ray fluorescence (XRF) technology for fast, accurate, and most importantly, nondestructive analysis of the precious metals that come into their shops. XRF quickly provides the exact karat weight and percentages of all elements within an item – easily identifying non-standard, under-karated, and even advanced counterfeit material.