Comparison · Quartz Family vs Minerals
Amethyst vs Fluorite
Amethyst and Fluorite are easy to confuse. Amethyst is harder (Mohs 7) than Fluorite (Mohs 4), so Amethyst will scratch Fluorite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Amethyst and Fluorite
- Amethyst is harder (Mohs 7) than Fluorite (Mohs 4), so Amethyst will scratch Fluorite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
- Fluorite feels noticeably heavier for its size (specific gravity 3.2 versus 2.65 for Amethyst).
- They overlap in purple, but Fluorite also comes in green, blue, yellow, clear, and pink.
- Well-formed crystals give it away: Amethyst is hexagonal, Fluorite is cubic.
Amethyst vs Fluorite properties
| Property | Amethyst | Fluorite |
|---|---|---|
| Type | Quartz Family | Minerals |
| Mohs hardness | 7 | 4 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | transparent | transparent |
| Specific gravity | 2.65 | 3.2 |
| Crystal system | hexagonal | cubic |
| Common colors | Purple, Violet, Deep Purple, Lavender | Purple, Green, Blue, Yellow, Colorless, Pink |
| Rarity | common | common |
| Typical specimen value | $10–$500+ | $5–$200+ |
Which is more valuable?
Amethyst is usually the more valuable of the two: a typical collector specimen runs about $50 against $25 for Fluorite, and premium Amethyst can reach $500 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 Fluorite
Fluorite is a colorful mineral that often exhibits multiple colors in a single specimen. It's the defining mineral for 4 on the Mohs hardness scale.
Amethyst vs Fluorite FAQ
Is Amethyst the same as Fluorite?
No. Amethyst is a quartz family while Fluorite is a mineral. Amethyst is harder (Mohs 7) than Fluorite (Mohs 4), so Amethyst will scratch Fluorite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
How can you tell Amethyst from Fluorite?
Amethyst is harder (Mohs 7) than Fluorite (Mohs 4), so Amethyst will scratch Fluorite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Fluorite feels noticeably heavier for its size (specific gravity 3.2 versus 2.65 for Amethyst). They overlap in purple, but Fluorite also comes in green, blue, yellow, clear, and pink.
Which is harder, Amethyst or Fluorite?
Amethyst is harder: Mohs 7 against Mohs 4 for Fluorite.
Which is more valuable, Amethyst or Fluorite?
Amethyst is usually the more valuable of the two: a typical collector specimen runs about $50 against $25 for Fluorite, and premium Amethyst can reach $500 or more.
