Onyx vs Smoky Quartz
Comparing Onyx and Smoky Quartz — two popular gemstones that share a similar color palette. On the Mohs scale, Onyx rates 6.5 and Smoky Quartz rates 7.0. In terms of price, Onyx falls in the moderately priced range and Smoky Quartz in the moderately priced range.
| Property | Onyx | Smoky Quartz |
|---|---|---|
| Category | Semi-Precious Gems | Semi-Precious Gems |
| Primary Color | black | various |
| Mohs Hardness | 6.5–7.0 | 7.0 |
| Specific Gravity | 2.55 | 2.65 |
| Refractive Index | 1.53 | 1.544 |
| Crystal System | Trigonal | Trigonal |
| Luster | — | — |
| Chemical Formula | — | — |
| Price Tier | Moderate ($50-500/ct) | Moderate ($50-500/ct) |
| Daily Wear | No | Yes |
Key Differences
- ◆ {'gem_a': '6.5', 'gem_b': '7.0', 'property': 'Hardness (Mohs)'}
- ◆ {'gem_a': 'Trigonal', 'gem_b': 'Trigonal', 'property': 'Crystal System'}
- ◆ {'gem_a': '2.55', 'gem_b': '2.65', 'property': 'Specific Gravity'}
- ◆ {'gem_a': '1.53', 'gem_b': '1.544', 'property': 'Refractive Index'}
- ◆ {'gem_a': 'N/A', 'gem_b': 'N/A', 'property': 'Luster'}
- ◆ {'gem_a': 'moderate', 'gem_b': 'moderate', 'property': 'Price Range'}
- ◆ {'gem_a': 'No', 'gem_b': 'Yes', 'property': 'Daily Wear'}
When to choose Onyx
Choose Onyx when you want its unique color and character. It's ideal for occasional wear pieces and pendants.
When to choose Smoky Quartz
Choose Smoky Quartz when you want superior hardness and scratch resistance, higher brilliance and light performance, and suitability for daily wear. It's ideal for engagement rings and everyday jewelry.
Frequently Asked Questions
Which is harder, Onyx or Smoky Quartz?
Smoky Quartz is harder at 7.0 on the Mohs scale, compared to Onyx at 6.5-7.0. This makes Smoky Quartz more resistant to scratching. Smoky Quartz is suitable for daily wear, while onyx requires more careful handling and is not ideal for daily wear.
Is Onyx more expensive than Smoky Quartz?
Onyx and Smoky Quartz are in a similar price range, both classified as moderately priced ($50-500/ct). Onyx typically ranges moderately priced ($50-500/ct), while Smoky Quartz ranges moderately priced ($50-500/ct).
Should I choose Onyx or Smoky Quartz for an engagement ring?
For an engagement ring, Smoky Quartz is the stronger choice with a durability rating of 7/10. At 7.0 Mohs hardness, it can withstand daily wear well. Onyx (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 Onyx and Smoky Quartz apart?
There are several visual cues: Onyx typically appears black while Smoky Quartz is various. A gemologist can confirm identification using refractive index testing.
Why do Onyx and Smoky Quartz look similar?
Onyx and Smoky Quartz look similar because both can show overlapping colors — Onyx is black and Smoky Quartz is various.