Alexandrite vs Moonstone

When choosing between Alexandrite and Moonstone — two birthstone gems often compared by jewelry buyers — consider that Alexandrite has a hardness of 8.5 Mohs and is fine/premium, while Moonstone has a hardness of 6.0 Mohs and is moderately priced.

Property Alexandrite Moonstone
Category Semi-Precious Gems Semi-Precious Gems
Primary Color various white
Mohs Hardness 8.5 6.0–6.5
Specific Gravity 3.69 2.56
Refractive Index 1.739 1.518
Crystal System Orthorhombic Monoclinic
Luster Vitreous
Chemical Formula
Price Tier Fine ($500-5,000/ct) Moderate ($50-500/ct)
Daily Wear Yes No

Key Differences

  • {'gem_a': '8.5', 'gem_b': '6.0', 'property': 'Hardness (Mohs)'}
  • {'gem_a': 'Orthorhombic', 'gem_b': 'Monoclinic', 'property': 'Crystal System'}
  • {'gem_a': '3.69', 'gem_b': '2.56', 'property': 'Specific Gravity'}
  • {'gem_a': '1.739', 'gem_b': '1.518', 'property': 'Refractive Index'}
  • {'gem_a': 'N/A', 'gem_b': 'Vitreous', 'property': 'Luster'}
  • {'gem_a': 'fine', 'gem_b': 'moderate', 'property': 'Price Range'}
  • {'gem_a': 'Yes', 'gem_b': 'No', 'property': 'Daily Wear'}

When to choose Alexandrite

Choose Alexandrite when you want superior hardness and scratch resistance, higher brilliance and light performance, premium quality and rarity, suitability for daily wear, and its significance as the modern June birthstone. It's ideal for engagement rings and everyday jewelry.

When to choose Moonstone

Choose Moonstone when you want a more budget-friendly price point. It's ideal for occasional wear pieces and pendants.

Frequently Asked Questions

Which is harder, Alexandrite or Moonstone?
Alexandrite is harder at 8.5 on the Mohs scale, compared to Moonstone at 6.0-6.5. This makes Alexandrite more resistant to scratching. Alexandrite is suitable for daily wear, while moonstone requires more careful handling and is not ideal for daily wear.
Is Alexandrite more expensive than Moonstone?
Yes, Alexandrite is generally more expensive. Alexandrite is classified as fine/premium ($500-5,000/ct) with prices around fine/premium ($500-5,000/ct), while Moonstone is moderately priced ($50-500/ct) at moderately priced ($50-500/ct).
Should I choose Alexandrite or Moonstone for an engagement ring?
For an engagement ring, Alexandrite is the stronger choice with a durability rating of 9/10. At 8.5 Mohs hardness, it can withstand daily wear well. Moonstone (6.0-6.5 Mohs) is softer and more prone to scratching with everyday use, making it better suited for occasional-wear jewelry.
How can I tell Alexandrite and Moonstone apart?
There are several visual cues: Alexandrite typically appears various while Moonstone is white; Alexandrite (RI 1.739-1.77) shows more brilliance than Moonstone (RI 1.518-1.527); they have different crystal systems — Alexandrite is Orthorhombic and Moonstone is Monoclinic. A gemologist can confirm identification using refractive index testing.
Can I use Alexandrite instead of Moonstone as a birthstone?
Yes, both Alexandrite and Moonstone are recognized birthstones for June. Alexandrite is the modern June birthstone and Moonstone is the alternative June birthstone, so either is an appropriate choice for that month.

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