The shrinking supply of traditional gemstones like diamonds, rubies, emeralds, sapphires, and pearls is pushing collectors and jewellers toward alternative stones, driving up prices for once-accessible options. Mine closures, depleted deposits, mining restrictions, and geopolitical disruption are constraining supplies of classic stones, while changing consumer tastes broaden demand.

Independent fine jewellery expert Joanna Hardy notes the industry now uses roughly 50 gemstones in jewellery making, moving away from labelling non-traditional stones as "semi-precious." Stones deemed durable, beautiful, and rare are increasingly considered precious.

Paraíba tourmalines exemplify this shift, with prices rising up to 45% last year and a stone selling for $311,000 per carat at Christie's 2025 New York Magnificent Jewels sale. Spinel prices have climbed 15% annually over the past decade, while pearl scarcity—linked to environmental changes—fuels interest in pink, silver, and lavender natural pearls.

Supply constraints are acute at the high end of the diamond market. Fewer than 30 natural red diamonds over one carot are known, with only three publicly recorded examples above five carats. Global rough diamond production fell from 176.7mn carats in 2005 to 98.8mn in 2025, a 44% decline over two decades.