Rare diamonds & colored gemstones Investment


If you are looking to diversify your investment portfolio, diamonds and rare colored gemstones should be put into consideration. Like with a piece of art, the beauty of a gemstone is that you have the option to enjoy it as long as it is in your possession. Diamonds are by far the most valuable asset you can own especially in comparison to their size. They are easy to store, move and sell, which makes them an attractive alternative to other physical assets.


Diamonds as an investment

In the past 15 years the value of 3 carat diamonds have increased by 145% and 5 carat diamonds have increased by 171% (source: Rapaport Diamond Trade Index).


With the exception of diamonds that are rare due to their size or color, diamonds are basically a commodity and for the most part your success as an investor will depend on the price you pay for it. It is really that simple.


Fancy diamonds

Fancy color diamonds are in a category of their own. They are graded according to the intensity of the colors they display, ranging from faint to vivid. Fancy diamonds come in nearly every color, however, the rarest and most desired amongst investors are red, green, pink and blue. Fancy diamonds are valuable for a reason, only 1 in 10,000 diamonds has a fancy color. This rarity has made fancy diamonds the ultimate gem for connoisseur investors and collectors over the past five years, which has driven the prices to extraordinary figures. The pricing is complex and heavily influenced by color, consumer taste and what others are willing to pay.


The finest specimens of the fancy color diamonds are rare to find on the market and they will only be available to the inner circle of the industry unless seen on auction.



Direct access to the source

For more than a decade Iver Rosenkrantz and his team have been in Africa working with artisanal miners to discover the source of gemstones. This allows us to provide our clients exclusive access to buy directly from the mines. By shortening the value chain, we are able to offer attractive prices for higher quality gemstones.


At Rosenkrantz we offer our expertise and networks to provide tailored investments and jewelry pieces for our clients.



Due to the nature of our business we offer full discretion. Whether you wish to sell or buy rare diamonds or colored gemstones, we offer our assistance and guidance ensuring that you get the best possible deal through a comfortable, convenient and safe process.



Any transaction, purchase or sale under our supervision or control will be managed through secure processes by our highly experienced team. Our service includes due diligence, certification, transportation and facilitation of transactions.


A lot of factors need to be taken into account when investing in diamonds. To some people it is a question of acquiring a family heirloom, which will be passed down to future generations, to some buyers it is purely business and to others it is a case of both. It all starts with a conversation.


Colored Gemstones

Investing in colored gemstones is a lot more complex than diamonds since small color variations can have significant influence on the price. Treatments are common and without reliable access, a buyer is at risk of financial loss and disappointment.


Knowing where to buy and sell is key.



Rubies, Sapphires & Emeralds


Due to over-mining, rubies, sapphire and emeralds are becoming more and more rare. Unlike tanzanite, which was only discovered in 1967, these gems have been known and desired for thousands of years. Along with diamonds these three gems are classified as “precious stones” and therefore there is no need to educate the market of their importance.


After fancy color diamonds, rubies are by far the most expensive gemstone followed by sapphire and emeralds. Some of the oldest rubies are more than 700 million years old. Regardless of whether a ruby is heated or unheated, of Burmese, Thai or African origin, finding a top color ruby of more than 3 carat has become very difficult. Rubies with a glow of clear “pigeon blood” color due to their high chromium and low iron content, have always been desired. Over the past decade the auction price of the finest rubies and sapphires have increased by approximately 1,000% and nearly 2,000% for the finest emeralds.




Due to the unique and complex geological conditions perfect for their formation, Tanzanite is only found in one place on earth, the foothills of Mt. Kilimanjaro. The exclusive mining area is approximately 7x2 kilometers and the miners have to go deeper and deeper to find the right quality. Currently, most of the mines are more than 1000 meters deep and inevitably the cost of extraction will go up as the mining progresses. The lifespan of the source is unknown and it is highly doubtful that tanzanite will be discovered anywhere else.


In 2019 Rosenkrantz created the largest tanzanite and diamond necklace in history. Our team specialises in sourcing the best gems whether it is for jewelry or purely for investment purposes.