Diamonds: Correlation
Prices it moves with, and why
Natural rough diamonds are sold by a few miners, led by De Beers and Alrosa, through sights and tenders, and mostly cut in India. Prices depend on jewellery demand in the US, China and India, and on cheap lab-grown stones.
Price index US import price index: gem diamonds index · monthly, Dec 2007 to Sep 2026What its price moves with
Selected linkDiamonds and Gold
Monthly changes 0.08 little or none correlation 12-month changes -0.17 little or none correlation Last 5 years 0.12 monthly changes Lead or lag none No clear lead or lag Price function, Dec 2007 to Sep 2026 Diamonds ≈ 115.4 × (Gold)-0.01 R² 0.01 On this fit, a 10% higher gold price goes with a −0.1% lower diamonds price over the long run. Units: index and $/troy oz. The fit is loose, so treat the function as a rough guide.Chart: Diamonds and Gold prices rebased to 100 at Dec 2007, log scale
Both prices rebased to 100 at Dec 2007, on a log scale so equal percentage moves look the same size.Chart: Diamonds price against Gold price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2007), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Gold and diamonds compete for jewellery budgets, and both depend on consumer wealth in India, China and the US. The index of US diamond import prices shows almost no tie with gold (0.08 monthly), since gold also acts as a financial asset.
little or none co-movement month to month · 224 months Show chartsPlatinum is a common setting for diamond rings, so bridal jewellery demand links the two. The correlation is slight, monthly moves 0.16 and yearly changes slightly negative (-0.09), because platinum's price is driven mainly by cars.
little or none co-movement month to month · 224 months Show chartsIndustrial diamonds, now almost all synthetic, are used in grinding, cutting and drilling tools alongside other abrasives. They do not affect gem prices much; the abrasives index shows a monthly correlation of 0.02 and yearly of 0.33.
little or none co-movement month to month · 222 months Show chartsLab-grown diamonds are grown by chemical vapour deposition from methane in a hydrogen plasma, so hydrogen is a direct input to the main competitor of mined stones. The hydrogen index shows no correlation with gem prices (0.03 monthly).
little or none co-movement month to month · 206 months Show chartsGrowing diamonds by vapour deposition or high-pressure presses takes a lot of electricity, so cheap power in India and China helps lab-grown stones undercut mined ones. The US power index correlates at 0.10 monthly and 0.37 yearly with the diamond index.
little or none co-movement month to month · 224 months Show chartsHow to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.