Reduce, reuse, recycle. Even though nearly five decades have passed since the catchy slogan was coined at the dawn of the environmental movement, in the diamond jewelry trade, the recycling message has only recently gone mainstream.

On some level, of course, diamonds have always been recycled (or, reused, as the diamond dealer Jared Holstein recently clarified in an interview). Throughout history, jewels have been dismantled and melted down when fashions changed or their owners needed a quick spot of cash. What’s new is that these stones are now being explicitly marketed as “post-consumer recycled” goods.

Although verifying the ethical provenance of such stones is difficult, if not impossible, it’s clear that “from an environmental perspective, a reused diamond is the stone with the lowest environmental impact,” says Holstein.

That’s one reason why designers are increasingly gravitating toward them.

New York–based Michelle Fantaci has used recycled diamonds in both her fine jewelry and bridal collections. “Recycled diamonds, for me, are another option, or path to the least harmful materials, along with recycled gold and responsible sourcing,” she says. “I do what I can to make conscious choices. One interesting aspect to them can be discovering their original cut—if they haven’t been recut.

San Francisco–based Sharon Zimmerman, the designer behind Sharon Z Jewelry, turned to recycled diamonds about eight years ago, when some of her suppliers began to offer them. “At the time, I thought that this was the best alternative to the less-traceable newly mined diamonds, especially for melee-size stones,” she says. “However, I still really wish that the industry as a whole was able to supply us small, independent jewelry designers with fully traceable diamonds that have a real and measurable economic benefit for workers in the global south.

When clients ask Zimmerman where her recycled gems are from and how they were acquired, she answers them honestly. “I am as transparent as I can be with them about the sourcing—that these were pulled from old or unused jewelry and recut or repolished as needed,” she says.