In the last few years, copper, zinc, and nickel have dominated the natural commodities market, providing a rate of return that’s nothing short of phenomenal. But those in the know say that their record is about to be beaten, due to the increased scarcity and huge demand for a specific form of one of the most common elements on earth — carbon. Carbon is found in every living thing, in the graphite we use for lubrication, and in soot, but it’s the special carbon crystals created deep underground by heat and horrendous pressure that are of particular interest here. We call them diamonds, and for the first time in 25 years, production of these precious gemstones is about to decline.

A harsh reality about mining is that no matter what you’re digging up in a particular location, whether it’s coal or its cousin, diamond, it’ll eventually play out. This is what’s starting to happen in many of the world’s older mines. The demand for diamond jewelry, as well as for the industrial diamonds used in grinding, polishing, cutting, and drilling, continues to rise, even as old diamond mines dry up. Although producers have recently identified new sources of diamonds — particularly in Canada, home of the oldest diamonds in the world — they simply can’t keep up with demand. It’s estimated that by 2015, diamond production will have dropped by at least 2 percent, even accounting for the inevitable increase in the production of synthetic diamonds. Prices for diamonds and diamond jewelry are set to soar to heights never seen before.

What does this mean for you? Well, for starters it means that you’d better grab that diamond engagement ring that you’ve had your eye on before the prices get out of hand. In fact, it might be a good idea to invest as heavily in diamonds as you can. Even if you prefer not to stock up on diamond jewelry, it would be a good idea to invest in loose diamonds. Not only is the available stock declining, but the population of people capable of purchasing diamonds and diamond jewelry is growing consistently, if only because living standards are rising in many developing regions. Both China and India, the two most populous countries in the world, have recently enjoyed economic booms, and the people in China particularly have taken to the global market economy like fish to water. Diamond purchases for China alone have doubled since 2001, and may well increase another 20 percent by the end of the year.

There are several ways you can invest in diamonds. The most direct way is to buy diamonds, either loose or in diamond jewelry. It’s up to you whether you want to put them to their proper use or hide them away in the family vault somewhere. Otherwise, consider the possibility of buying shares in a financial fund that invests heavily in diamond stocks, since all diamonds, both industrial or gemstone quality, are likely to go up in value.

Unless synthetic diamonds completely overwhelm the market, it’s likely that diamond prices will continue to rise steadily for the foreseeable future. Although Tiffany and Co., DeBeers, and other diamond companies are busily spending megabucks working new diamond finds in Canada and elsewhere, older mine in Botswana and other classic diamond-producing regions are playing out. DeBeers has gone to the extreme of reopening a diamond mine that’s been shut for 97 years, in hopes that new techniques of mining and extraction can eke out a few thousand more carats of the shiny stuff.

To put it bluntly, if you want to make a mint — or if you just want to get that diamond wedding ring you’ve always dreamed about — better strike when the iron’s hot. By this time next year, diamond prices will be out of sight.