Comparison · Quartz Family vs Silicate Minerals
Amethyst vs Sugilite
Amethyst and Sugilite are easy to confuse. Amethyst is harder (Mohs 7) than Sugilite (Mohs 6), so Amethyst will scratch Sugilite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Amethyst and Sugilite
- Amethyst is harder (Mohs 7) than Sugilite (Mohs 6), so Amethyst will scratch Sugilite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
- Hold a thin edge to the light: Amethyst is transparent, Sugilite is translucent.
- They overlap in purple, but Sugilite also comes in pink, brown, and yellow.
Amethyst vs Sugilite properties
| Property | Amethyst | Sugilite |
|---|---|---|
| Type | Quartz Family | Silicate Minerals |
| Mohs hardness | 7 | 6 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | transparent | translucent |
| Specific gravity | 2.65 | 2.74 |
| Crystal system | hexagonal | hexagonal |
| Common colors | Purple, Violet, Deep Purple, Lavender | Purple, Violet, Magenta, Pink, Brownish yellow |
| Rarity | common | rare |
| Typical specimen value | $10–$500+ | $15–$1200+ |
Which is more valuable?
Sugilite is usually the more valuable of the two: a typical collector specimen runs about $150 against $50 for Amethyst, and premium Sugilite can reach $1200 or more.
About Amethyst
Amethyst is a purple variety of quartz and is the traditional birthstone for February. It's prized for its beautiful purple color ranging from light lavender to deep violet.
About Sugilite
Sugilite is a rare lithium-bearing cyclosilicate best known for its vivid purple to magenta gem material. It usually occurs as massive aggregates rather than crystals and is used as an ornamental and lapidary stone.
Amethyst vs Sugilite FAQ
Is Amethyst the same as Sugilite?
No. Amethyst is a quartz family while Sugilite is a silicate mineral. Amethyst is harder (Mohs 7) than Sugilite (Mohs 6), so Amethyst will scratch Sugilite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
How can you tell Amethyst from Sugilite?
Amethyst is harder (Mohs 7) than Sugilite (Mohs 6), so Amethyst will scratch Sugilite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Hold a thin edge to the light: Amethyst is transparent, Sugilite is translucent. They overlap in purple, but Sugilite also comes in pink, brown, and yellow.
Which is harder, Amethyst or Sugilite?
Amethyst is harder: Mohs 7 against Mohs 6 for Sugilite.
Which is more valuable, Amethyst or Sugilite?
Sugilite is usually the more valuable of the two: a typical collector specimen runs about $150 against $50 for Amethyst, and premium Sugilite can reach $1200 or more.
