mineral

Alexandrite in Matrix

Chrysoberyl (BeAl2O4 with Chromium impurities)

Hardness: 8.5 Mohs scale; Color: Green in daylight, red in incandescent light (pleochroic); Luster: Vitreous; Crystal Structure: Orthorhombic; Cleavage: Distinct/Good on one plane; Specific Gravity: 3.5–3.8

Hardness: 8
Color: Green in daylight, red in incandescent light (pleochroic)
Luster: Vitreous

Identified March 2, 2026More mineral →

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Physical properties

Formation & geological history

Forms in granitic pegmatites and mica schists where beryllium and chromium meet, a rare geological coincidence. Major deposits are found in metamorphic rocks formed millions of years ago, such as those in the Ural Mountains or Brazil.

Uses & applications

Primarily used as a high-value gemstone for jewelry due to its extreme rarity and color-changing properties. Also a highly sought-after specimen for mineral collectors.

Geological facts

Alexandrite was famously named after Tsar Alexander II of Russia because it was discovered in the Ural Mountains on his birthday in 1834. It is often described as 'emerald by day, ruby by night.'

Field identification & locations

Identify in the field by checking for the 'alexandrite effect' (color change under different light sources). Commonly found in the Ural Mountains (Russia), Minas Gerais (Brazil), Sri Lanka, and Tanzania. Collectors look for well-defined hexagonal or pseudo-hexagonal twinning in the matrix.

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