ANCHORAGE, Alaska (AP) — The growing list of jewelers vowing to boycott gold from the proposed Pebble Mine in Alaska now includes major manufacturers of class rings.

Herff Jones and Commemorative Brands Inc., both of which make class rings, have joined the list of jewelers opposed to the proposed mine in southwest Alaska. Two other companies, Birks and Mayors and Hacker Jewelers, also added their names to the list on Wednesday.

Canadian-based Northern Dynasty Minerals Ltd. and London-based Anglo American are developing the minerals deposit. The huge copper, gold and molybdenum deposit is near some of the world's most productive wild salmon streams.

The 18 jewelry companies against Pebble represent sales of more than $3.7 billion a year.

John Shively, CEO of the Pebble Partnership, said the jewelers are premature in opposing the Pebble mine because the project plans have not been finalized.

"They've prejudged the project when we don't have one. I think it is unfortunate but that is their decision," he said.

Northern Dynasty and Anglo American recently announced a $10 million increase in this year's budget for Pebble to prepare the mine for state and federal permitting starting next year.

Dan Hacker, whose father founded Hacker Jewelers of Tecumseh, Mich., in 1956, described his business as a "mom and pop" operation.

"Certainly, I am not a crazy person that is against all kinds of economic development or anything, but this proposal is a very big open pit mine, perhaps the biggest open pit mine in North America, and it really threatens to endanger a great commercial salmon fishery and some pristine water," Hacker said Wednesday. "The salmon fishery provides tens of thousands of jobs for people and that is a sustainable industry."

Hacker also said that while his business is small compared to some of the others opposed to Pebble, he tries to do his part to run it responsibly. Whenever possible, he said he uses recycled gold instead of newly mined gold.

"Gold is one of the most recycled resources that the world has ever known," he said.

Tiffany & Co., with more than $1.5 billion in sales, is leading the campaign against Pebble. It took out an advertisement in an issue of National Jeweler to encourage other jewelers to join the campaign.

"Despite the best of intentions, 175 years of experience sourcing gemstones and precious metals tells us that there are certain places where mining cannot be done without forever destroying landscapes, wildlife and communities," it read. "Bristol Bay is one such place."

Other large jewelers who have said they oppose the mine include Herff Jones and Helzberg Diamonds.

John Orrico, senior vice president of Birks and Mayors, said the company was proud to join other "responsible jewelers denouncing the proposed mining of precious metals at Bristol Bay."

"We trust that the jewelry industry will stand in support of the Bristol Bay salmon fishery thereby preserving this ecosystem while continuing to develop sustainable and responsible sources of supply," Orrico said.

Most of the demand for gold in the United States is for jewelry.