Editor’s Note
Recent data from the International Diamond Exchange reveals a significant shift in the diamond market, challenging long-held perceptions of the gemstone as a stable store of value. This article examines the factors behind the surprising price trends.
“A Diamond is Forever.” This advertising slogan created by De Beers in 1947 is considered one of the most successful marketing campaigns of the 20th century, imprinting diamonds as a symbol of ‘unchanging value’ and ‘eternal love.’ However, that belief, which seemed eternal, is now crumbling in the face of recent market data.
The price index published by the International Diamond Exchange (IDEX) is overturning common perceptions about the value of diamonds. This article will analyze the rapid changes in the diamond market through specific data and examine the structural reasons why diamond and gold prices are moving in opposite directions.
The IDEX price index starkly shows the collapse of the diamond market. After reaching a historical high of 158.39 on March 7, 2022, it fell to 86.08 by November 27, 2025. This represents a drop of approximately 45.6% from the peak, meaning the price has nearly halved in just over two years.
This is not a simple temporary adjustment. Looking at the trend line on the graph, the downtrend is still ongoing, with no clear bottom signal in sight. This continuous decline reflects a structural change in the market.
The rapid growth of lab-grown diamonds
The most decisive factor in the decline of diamond prices is the emergence of lab-grown diamonds. With advancements in CVD (Chemical Vapor Deposition) and HPHT (High Pressure High Temperature) technologies, it has become possible to mass-produce artificial diamonds that are physically and chemically identical to natural diamonds.
According to market research firm Paul Zimnisky, the market share of lab-grown diamonds surged from about 2% in 2020 to about 20% in 2023. More importantly, production costs are continuously falling. While the mining cost for natural diamonds is about $100-$150 per carat, lab-grown diamonds, which were at the $300-$500 level, are rapidly becoming cheaper due to technological advancements.
The end of the De Beers monopoly
Throughout the 20th century, De Beers controlled 80-90% of the world’s diamond supply, maintaining artificial scarcity. However, since the 2000s, with the emergence of new producing countries like Russia (Alrosa), Australia, and Canada, its monopoly power has weakened. As of 2023, De Beers’ market share is estimated to be around 30%.
Changing values of Millennials and Gen Z
According to Bain & Company’s 2023 Global Diamond Industry Report, Millennials and Gen Z have significantly lower preference for natural diamonds compared to previous generations. They are sensitive to environmental destruction from the mining process and the issue of conflict diamonds (Blood Diamonds), and tend to place higher value on ‘experiences.’
In reality, the percentage of people who consider diamonds essential when purchasing an engagement ring has decreased from about 75% among Baby Boomers to about 40% among Millennials.