10/30/2013 01:33 pm ET

Buy That Engagement Ring Now: The Coming Supply Squeeze In Diamonds

Flickr: Randi Deuro

Couples thinking about getting married someday might want to consider way-in-advance planning for the ring. Diamond prices will not be getting any cheaper and might even soar in about four years.

That’s when existing diamond mines will start to tap out and producers won’t be able to fully replace the loss of supply. The fundamentals of demand growth, meanwhile, remain firmly in place. As a result, there could be steep increases in diamond prices starting in 2018, new analysis by Bain & Company projects