Does Sri Lanka have natural diamonds?

No, Sri Lanka does not produce natural diamonds. The island’s geology is amazingly fertile for coloured gemstones like corundum and pegmatite minerals; however, it misses the deep volcanic kimberlite pipes that are needed to form diamonds.

So any diamonds you see for sale in Sri Lankan jewellery shops are brought in from global markets, usually Dubai, India, or Antwerp, and then they get set next to local sapphires. Because of that, buying diamond jewellery in Sri Lanka is usually not cost-effective for tourists; you end up paying the imported premium rather than something locally sourced.