Comparison · Minerals vs Quartz Family
Fluorite vs Quartz
Fluorite and Quartz are easy to confuse. Quartz is harder (Mohs 7) than Fluorite (Mohs 4), so Quartz 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 Fluorite and Quartz
- Quartz is harder (Mohs 7) than Fluorite (Mohs 4), so Quartz 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 Quartz).
- Hold a thin edge to the light: Fluorite is transparent, Quartz is Transparent to translucent.
- They overlap in purple, yellow, clear, and pink, but Fluorite also comes in green and blue and Quartz also comes in black, gray, and brown.
- Well-formed crystals give it away: Fluorite is cubic, Quartz is Trigonal.
Fluorite vs Quartz properties
| Property | Fluorite | Quartz |
|---|---|---|
| Type | Minerals | Quartz Family |
| Mohs hardness | 4 | 7 |
| Luster | vitreous | Vitreous, greasy on fracture surfaces |
| Streak | White | White |
| Transparency | transparent | Transparent to translucent |
| Specific gravity | 3.2 | 2.65 |
| Crystal system | cubic | Trigonal |
| Common colors | Purple, Green, Blue, Yellow, Colorless, Pink | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $5–$200+ | $5–$250+ |
Which is more valuable?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $25 for Fluorite, and premium Quartz can reach $250 or more.
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.
About Quartz
Quartz is silicon dioxide, SiO2, one of the most abundant minerals in Earth's continental crust, crystallizing in the trigonal division of the hexagonal crystal system with a hardness of 7 that makes it a standard reference point on the Mohs scale. Its six-sided prismatic crystals, often terminated by pyramidal points, are among the most recognizable crystal shapes in mineralogy. Quartz occurs in nearly every rock type and geologic setting, from granite pegmatites to sedimentary sandstones to hydrothermal veins.
Fluorite vs Quartz FAQ
Is Fluorite the same as Quartz?
No. Fluorite is a mineral while Quartz is a quartz family. Quartz is harder (Mohs 7) than Fluorite (Mohs 4), so Quartz 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 Fluorite from Quartz?
Quartz is harder (Mohs 7) than Fluorite (Mohs 4), so Quartz 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 Quartz). Hold a thin edge to the light: Fluorite is transparent, Quartz is Transparent to translucent.
Which is harder, Fluorite or Quartz?
Quartz is harder: Mohs 7 against Mohs 4 for Fluorite.
Which is more valuable, Fluorite or Quartz?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $25 for Fluorite, and premium Quartz can reach $250 or more.
