Sarah Greenberg, a jewelry designer in Oakland, California, used to craft half of her collection from gold. Now, she doesn’t even carry pieces made from the precious metal in stock.

“Bronze has become the gold alternative to me, offering that warm and yellow look,” said Greenberg, 32, who’s been promoting the copper-and-tin alloy to local boutiques lately. “It’s the only way to ensure that the general public can purchase my jewelry.”

Greenberg isn’t alone in pushing alternative materials. Zale Corp., Tiffany & Co. and Pandora Jewelry LLC all are promoting metals such as palladium, bronze and other alloys in their product lines to attract customers who can no longer afford pieces made from more expensive metals.

Since 2000, gold has climbed sixfold and platinum has more than doubled while median U.S. income has slid 7 percent, adjusted for inflation. The higher prices may contribute to a 4.3 percent decline in gold jewelry demand this year and an additional 3.9 percent drop next year, Barclays Capital said in a report last month.

The trends are forcing jewelers to get creative with their accessory choices to lure customers and maintain profit margins, said Betty Chen, a San Francisco-based analyst at Wedbush Securities.

Zale offers titanium wedding bands for less than one tenth the price of gold rings. Online retailer Blue Nile Inc. features palladium wedding bands on its website for $415 to $840, less than half the prices of comparable platinum pieces. Necklaces in the fall collection for Francesca’s Holdings Corp. are marketed as “golden” while selling for less than $100.

Adding Offerings

“Brands are trying to add to their accessories offerings and bring in as many people as possible,” Chen said in an interview.

While gold is being displaced by bronze, platinum may be replaced by palladium, a white-colored metal in the same family that sells for about 40 percent of the price. The metal, which also is used in automobiles’ catalytic converters, has dropped by more than a third since 2000.

Palladium is appealing because aside from being cheaper than gold or platinum, it doesn’t tarnish like bronze or silver, said Brooke Brinkman, spokeswoman for the Billings, Montana- based Palladium Alliance International. The group is funding an ad campaign for the metal that features former “Baywatch” star Pamela Anderson and fashion designer Kelly Osbourne touting palladium.

Receptive Consumers

Consumers in their 20s may be the most receptive to jewelry made from non-traditional materials, said Pam Danziger, president of Unity Marketing, a Stevens, Pennsylvania-based research firm. Younger buyers may view gold more practically, Danziger said.

“They’re saying, ‘Gold is an investment, not for something as frivolous as jewelry,’” she said.

People older than the age of 40 may be harder to win over because they grew up with the idea that only platinum and gold are true quality, Danziger said.

Brands like Tiffany, whose higher-income shoppers are more immune to price increases, may not have to adjust as much as chains such as Zale, said Dorothy Lakner, an analyst at Caris & Co. in New York, who said jewelry prices have increased about 15 percent in the past year.

“The higher-end the brand, the easier it is going to be to pass on price increases,” Lakner said in a telephone interview. “It’s the lower price-point customers who get fed up easily and say enough is enough.”

Tiffany Prices

Tiffany already has raised prices in 2011, and Chief Operating Officer James Fernandez said at a presentation in June that the company’s customers are able to accept such increases. The company’s shares have climbed 14 percent this year in New York, while Zale has dropped 17 percent and Blue Nile has slid 24 percent.

Still, Tiffany offers rose gold, an alloy of the precious metal and copper, on chains and its signature lock pendant for less than $250, about half the price of its cheapest regular gold items.

Until ordinary consumers fully embrace the precious-metal alternatives, retailers may continue to market their pieces as tried-and-true classics, Lakner said.

“No one wants to openly wear something they consider to be less than quality,” Lakner said. “Even if bronze is the new gold, they are likely to pass it off as something else.”