Can inclusions increase a gemstone’s value?

Yes, certain rare and visually appealing inclusions can boost a gemstone’s worth quite a bit, mainly because they prove its natural origin or they bring about special optical effects that are hard to copy. People often point to horsetail inclusions inside demantoid garnets and rutile silk within sapphires as the best-known examples, and honestly, they do stand out.

In general, inclusions tend to push a stone toward a lower clarity grade, but in a few cases, very specific internal features act like microscopic fingerprints. Gemmologists lean on those details to confirm the stone is unheated, or to narrow down where it was formed, like when they identify a highly prized Kashmir sapphire. On top of that, well-organised inclusions, for instance, rutile needles, can create sought-after optical phenomena: asterism (the star effect) in star sapphires, and chatoyancy (the cat’s-eye effect) in chrysoberyl. When these traits show up, the market price often climbs fast.