Introduction: Why Alexandrite Remains One of the Rarest Gemstones on Earth

Alexandrite is one of the scarcest gemstones available to collectors today. Its rarity comes from a combination of geological difficulty, narrow formation conditions, tight global supply, and a natural optical effect that very few minerals possess. Quality alexandrite color change will evolve from chrysoberyl with the presence of both chromium and the absence of iron during formation. These conditions rarely occur in the same geological environment. As a result, fine Alexandrite is far rarer than ruby, emerald, sapphire, and even most fancy color diamonds.

Alexandrite’s signature trait is its ability to change color under different lighting conditions. Daylight usually reveals a green or bluish green tone while incandescent or warm light reveals a pink, purplish red, or purple tone. The strength of that color change influences value more than almost any other factor. A stone that shifts 80 to 100 percent between two distinct hues is significantly more desirable than stones with only mild or partial change.

Untreated Alexandrite with strong color change is rare across all sizes. Above 2 carats, supply becomes limited. Above 4 carats, true fine material becomes exceptionally scarce. Once a stone reaches 6 to 8 carats, it falls into a category that only a handful of collectors in the world can pursue.

Comparatively speaking, prior years had stronger Alexandrite sales per carat, and larger sizes. This further supports evidence that the gem continues to dwindle in availability. Collectors seem to show more interest in Brazilian Origin Alexandrites, yet the presence of Alexandrites from Africa continue to show a slight increase in demand as buyers are ready for other sources. Below you will find some of the rarest Alexandrites sold this year based on quality, origin, and shape. Pairs are hard to find. Ring or Jewelry design was given little wait. Some prices were higher due to brand prestige. We just considered the gemstone itself (not any diamonds included with it when listing price per ct).

TOP TEN RESULTS OF 2025

1. 8.97 Carat Brazilian Alexandrite Ring (Christie’s Online)

Date: December 5, 2025

Estimate: HKD 200,000 to 300,000

Sold: HKD 1,778,000 (USD ≈ 227,600)

Price Per Carat: ≈ 25,380 USD per carat

Details:

This stone was one of the largest Alexandrite sold at auction in 2025. At 8.97 carats with Brazilian origin(dual reports from SSEF and GIA). The stone achieved one of the more modest prices per carat for its origin class. The color shift was described as moderate green blue to reddish purple. The stone had inclusions and a small chip which may have accounted for the price discount.

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