Diamonds to us are wonderful accent gems like a lovely frame on a masterpiece. It is no mystery that we, like generations before us dating back to Ancient days love colored gems.
Diamond has the illusion of being rare, thanks to careful release and stockpiling of the material in massive underground vaults by the controlling companies. Colored diamonds and very large, well-cut, clear diamonds above 5 carats are apt to gain in value. VS1 to Internally Flawless clarity and D color are the best investment gems, along with colored diamonds (brown diamonds are on the fence with us,) are rare and gaining ground. The brown colored diamonds they used to use in industrial grinders and saws but now they have been marketed wisely with food like names and they suddenly gained value.
The illusion that diamonds are rare keeps the price up. Diamonds under 5 carats are not very rare in the gemological world. But, they have maintained and gained in value with excellent color, clarity and cut. Now, the manmade diamond business has taken a dent out of the market. Manmade diamonds are after all real diamonds just made in a lab.
But never fear, the price of your diamonds are still steadily going up due to inventory management and careful release of the material, and marketing.
Diamond was NOT a very popular engagement ring gem until heavy marketing after the turn of the 20th century popularized it. Santa Clause was green and white until Coca-Cola did an ad campaign with him wearing their colors and it stuck. Marketing is crafty, but beware getting caught in trends. Check Christie's Auction house website and search gems that are for sale and how much a gem sold for in past auctions, Sotheby's is another great place to establish value but pay attention to dates because art and gems can go up fast and some luxury items go down.
The diamond market has been flooded with Moissanite which is difficult to detect and is as beautiful, many think more beautiful than natural diamond and more affordable. It is, manmade real diamond virtually the same in composition as an earth mined diamond. Like diamond, Moissanite (or other brand name manmade diamond,) can be lower and higher quality. Many people are beginning to use Moisanite and other brands of manmade diamonds in their jewelry, not wanting to pay for a stone that is rare only due to corporate finagling.
One thing remains true. Diamond gives colored gems more beauty when used as accent gems. Clear or "white," diamonds can go with virtually any gem in a jewelers palette. And, they will likely continue to have value as long as the markets are not flooded. The words, "Blood Diamond," refer to diamonds obtained from dangerous African mines which are often controlled by militia. Large Diamond empires became worried that these mines would flood the market with diamonds and dilute the myth that diamonds are rare. This was likely the biggest driving force behind stopping import of "Blood Diamonds," and rallying a social movement around buying "conflict free," diamonds which have historically never been conflict free.