The most expensive commonly recognized birthstone today is generally alexandrite , a rare color‑changing gem associated with June, with top stones reaching well over $15,000–$20,000 per carat, sometimes even higher for exceptional quality pieces.

Why alexandrite tops the list

  • High‑end natural alexandrite can range from about $15,000 to $70,000 per carat for exceptional color change and clarity, putting it above fine diamond on a per‑carat basis.
  • It is extremely rare in nature, especially in larger sizes with strong green‑to‑red color change, which drives its value sharply up.

Where diamond fits in

  • Diamonds are still one of the most expensive and famous birthstones, with quality stones often quoted from roughly $3,000 to $15,000+ per carat depending on color, clarity, and size.
  • In many commercial “most expensive birthstone” lists focused on popular jewelry, diamond is labeled the ultimate luxury birthstone because of huge demand and brand prestige, even though the very top alexandrite prices can surpass it.

Other pricey birthstones

  • Fine rubies and emeralds also sit near the top tier, often in the $3,000–$12,000 per carat range for high‑quality stones, especially from premium origins like Burma (ruby) or Colombia (emerald).
  • Some rankings focused on “average” high‑quality jewelry pieces (rather than record‑breaking collector stones) may still place diamond above alexandrite, which is why different sites sometimes disagree on which is “most expensive.”

Mini FAQ: “Most expensive birthstone” confusion

  • If the question is “Which birthstone can reach the highest price per carat?” the answer is usually alexandrite.
  • If the question is “Which birthstone is the most expensive overall in mainstream fine jewelry? ” many jewelers will still say diamond because it dominates the luxury market and consistently commands high prices across a wide range of qualities.

Information gathered from public forums or data available on the internet and portrayed here.