Amethyst vs Tanzanite
When choosing between Amethyst and Tanzanite — two popular gemstones that share a similar color palette — consider that Amethyst has a hardness of 7.0 Mohs and is moderately priced, while Tanzanite has a hardness of 6.5 Mohs and is moderately priced.
| Property | Amethyst | Tanzanite |
|---|---|---|
| Category | Semi-Precious Gems | Semi-Precious Gems |
| Primary Color | purple | various |
| Mohs Hardness | 7.0 | 6.5–7.0 |
| Specific Gravity | 2.65 | 3.35 |
| Refractive Index | 1.544 | 1.685 |
| Crystal System | Trigonal | Orthorhombic |
| Luster | — | — |
| Chemical Formula | — | — |
| Price Tier | Moderate ($50-500/ct) | Moderate ($50-500/ct) |
| Daily Wear | Yes | No |
Key Differences
- ◆ {'gem_a': '7.0', 'gem_b': '6.5', 'property': 'Hardness (Mohs)'}
- ◆ {'gem_a': 'Trigonal', 'gem_b': 'Orthorhombic', 'property': 'Crystal System'}
- ◆ {'gem_a': '2.65', 'gem_b': '3.35', 'property': 'Specific Gravity'}
- ◆ {'gem_a': '1.544', 'gem_b': '1.685', 'property': 'Refractive Index'}
- ◆ {'gem_a': 'N/A', 'gem_b': 'N/A', 'property': 'Luster'}
- ◆ {'gem_a': 'moderate', 'gem_b': 'moderate', 'property': 'Price Range'}
- ◆ {'gem_a': 'Yes', 'gem_b': 'No', 'property': 'Daily Wear'}
When to choose Amethyst
Choose Amethyst when you want superior hardness and scratch resistance, suitability for daily wear, and its significance as the modern February birthstone. It's ideal for engagement rings and everyday jewelry.
When to choose Tanzanite
Choose Tanzanite when you want higher brilliance and light performance, and its significance as the modern December birthstone. It's ideal for occasional wear pieces and pendants.
Frequently Asked Questions
Which is harder, Amethyst or Tanzanite?
Amethyst is harder at 7.0 on the Mohs scale, compared to Tanzanite at 6.5-7.0. This makes Amethyst more resistant to scratching. Amethyst is suitable for daily wear, while tanzanite requires more careful handling and is not ideal for daily wear.
Is Amethyst more expensive than Tanzanite?
Amethyst and Tanzanite are in a similar price range, both classified as moderately priced ($50-500/ct). Amethyst typically ranges moderately priced ($50-500/ct), while Tanzanite ranges moderately priced ($50-500/ct).
Should I choose Amethyst or Tanzanite for an engagement ring?
For an engagement ring, Amethyst is the stronger choice with a durability rating of 7/10. At 7.0 Mohs hardness, it can withstand daily wear well. Tanzanite (6.5-7.0 Mohs) is softer and more prone to scratching with everyday use, making it better suited for occasional-wear jewelry.
How can I tell Amethyst and Tanzanite apart?
There are several visual cues: Amethyst typically appears purple while Tanzanite is various; Tanzanite (RI 1.685-1.707) shows more brilliance than Amethyst (RI 1.544-1.553); they have different crystal systems — Amethyst is Trigonal and Tanzanite is Orthorhombic. A gemologist can confirm identification using refractive index testing.
Why do Amethyst and Tanzanite look similar?
Amethyst and Tanzanite look similar because both can show overlapping colors — Amethyst is purple and Tanzanite is various.