I'd started to think that all that glitters comes at a terrible cost to the environment.

After all, producing a single gold ring leaves behind 20 tons (!) of waste. Some of that waste includes toxins used to unearth the gold, such as mercury and sodium cyanide that leech into water supplies and contaminate resources.

And anyone who caught Blood Diamond, the 2006 movie starring Leonardo DiCaprio, surely has qualms about asking Santa for diamonds.

So, I was glad to stumble across an article in Canada's National Post about the growing trend toward sustainable jewelry — or as they put it, enviro-bling.

It's a bit of work, but it is possible to find companies that focus on responsible buying, selling, and mining practices. Several emphasize the importance of recycling materials, rather than mining new ones.

Of course, recycled jewelry is not a new phenomenon. Personally, I'm a big fan of the handmade goods found at sites like Etsy. It is, among other things, a virtual clearinghouse of creative ways to transform trash into treasure and a great place to shop for holiday gifts.

But if earrings made from old typewriter keys and bike parts won't cut it, it's great to know about other options. Here are some places to start: 

• Buy Canadian diamonds. Their diamonds are guaranteed to by blood-free (although there is some argument about how environmentally-friendly they are). Try Brilliant Earth, which only sells conflict-free diamonds and uses recycled gold and platinum. They sell loose diamonds, as well as jewelry that rivals anything from Tiffany's. And, they donate five percent of their profits to African communities.

• Amnesty International USA has a Diamond Buyers Guide, which provides a list of four questions — like "where did the diamonds come from," and "what is your policy on diamond-buying?" — to ask retailers.  The goal, it seems, is to alert and convince jewelers that ethics are a consideration for many buyers.   

• Look for retailers affiliated with NoDirtyGold.org. They have agreed to gold mining practices that respect human rights and the environment. The good news is that a surprising number of major retailers, including Wal-Mart and QVC, have signed on, as have well-known jewelry dealers, including Tiffany's, Zales and Van Cleef & Arpels. The bad news is they may not sell conflict-free diamonds. 

• Check out Ethical Metalsmiths, which helps connect people to responsibly-sourced materials. Among other things, they recruit volunteer jewelers, and ask all of us to "mine" our jewelry cases for raw materials that can be refashioned into something new.