Throughout the 1920s, prices on the U.S. stock exchange rose exponentially, however, by the end of the decade, uncontrolled growth and a stock market propped up by speculation and borrowed money proved unsustainable, resulting in the Wall Street Crash of October 1929. This set a chain of events in motion that led to economic collapse - banks demanded repayment of debts, the property market crashed, and people stopped spending as unemployment rose. Within a year the country was in the midst of an economic depression, and the economy continued on a downward trend until late-1932.

It was during this time where Franklin D. Roosevelt (FDR) was elected president, and he assumed office in March 1933 - through a series of economic reforms and New Deal policies, the economy began to recover. Stock prices fluctuated at more sustainable levels over the next decades, and developments were in line with overall economic development, rather than the uncontrolled growth seen in the 1920s. Overall, it took over 25 years for the Dow Jones value to reach its pre-Crash peak.

In 1960, the average price for such a diamond stood at some 2,700 U.S. dollars. Since then, the diamond price has increased more than tenfold, to 29,650 U.S. dollars in 2015.

Diamond prices: carats to dollars

Diamonds are a carbon-based gemstone coveted by innumerable people worldwide. They are among the hardest materials on Earth (if not the hardest), which makes them very valuable for industrial uses in addition to their wide use in luxury jewelry. Diamonds are also expensive. The cut, clarity, color, and carat (weight and size) are the so-called four 'Cs' that dictate a diamond's price. One carat is equal to a weight of approximately 200 milligrams, and cost approximately 29,650 U.S. dollars in 2015. Diamond prices per carat show a consistent increasing trend, while the annual rough diamond production worldwide has sat between 128 million carats and 152 million carats between 2009 and 2019.

Impact of the diamond demand-supply gap on prices

As the known global diamond reserves continue to be mined and depleted while the global demand for diamonds increases, a diamond demand-supply gap is expected to develop in the coming years. By 2050, there is a forecasted supply shortfall of some 278 million carats of diamonds worldwide. This will likely cause the price per carat to continue increasing for natural diamonds. The production of synthetic diamonds, also referred to as lab grown diamonds, is a potential solution to the projected diamond shortfall. There was a steady production of between 4.37 and 4.42 billion carats of synthetic diamonds worldwide between 2007 and 2016. Synthetic diamonds also cost between 30 and 40 percent less than a natural diamond does, but not every consumer is willing to forgo natural diamonds in favor of a diamond that has been created in a lab.

Graph and download economic data for Index of Wholesale Prices of Lumber for United States (M0464AUSM336NNBR) from Jan 1913 to Dec 1951 about wood, wholesale, price index, indexes, price, and USA.