Initially, the diamond industry was almost exclusively controlled by De Beers. This brand covered 85% of the global supply of diamonds for almost the entire 20th century. However, starting in the 1950s, diamonds began to be mined in Russia, Australia and Canada. Developments in these countries have effectively cut De Beers’ stake in half.

New entrants to the diamond market did not join De Beers’ monopoly policy. However, diamond prices are still maintained and controlled by several of the largest producers, and there is no doubt that their key interest is to avoid excessive fluctuations in the price of these precious gems. To some extent, all of them can control the polished market from the side of their supply – by reducing or increasing the share of diamonds offered for sale. The only thing they have no influence over is the huge quantities of stones sold prior. If end buyers suddenly decide to put their own diamonds up for sale, prices could plummet.

The rough diamond market is formed by the largest international diamond mining corporations: De Beers (Luxembourg), Rio Tinto (Great Britain) and ALROSA (Russia). If production (that is, “supply”) rises, the largest producers can step in and buy out or otherwise prevent oversupply to keep prices from falling.

Prices for the final product – cut diamonds themselves – are published monthly in the Rapaport Corp. price list Rapaport analysts research trends and prices around the world. Diamond traders in all countries follow the Rap List and use it as a standard to set their own prices. For the wholesale trade in diamonds, a report price list is also usually used, from the prices of which an agreed discount is made.

How are prices for precious and semi-precious stones formed?

In contrast to the history of the diamond market, prices for colored (precious and semi-precious) stones are more a function of the classic “supply and demand”. There are not many large mining companies in this market, and most of the manufacturers are much smaller in scale compared to the diamond giants. Typically, these organizations do not have sufficient funds to control production or demand. As a result, gem prices reflect their true value rather. More importantly, many gems are much rarer than diamonds, so a “crisis of overproduction” is impossible.

In general, the value of gems is determined by their rarity (uniqueness), beauty, durability and “portability”. The well-known 4Cs (color, cut, clarity and carat weight) are important for evaluating and comparing stones within the same category. When comparing different types of stones to each other, uniqueness and weight become equally important.

Some stones – for example red beryl (bixbit) or benitoite – don’t even have to be beautiful or particularly clean in order to be appreciated. These stones are no longer mined, and collectors value them precisely for their super high indicators of color and uniqueness. Even stones with a high proportion of inclusions are in high demand, especially if their weight exceeds 1 carat.

In some cases, gems are judged in a very strange way. For example, the asking price for an unusual stone or mineral from the mines of Myanmar can be as high as $ 5,000, as opposed to $ 10 for a similar stone on ebay.