Comparison · Minerals vs Quartz Family
Diaspore vs Quartz
Diaspore and Quartz are easy to confuse. Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Diaspore and Quartz
- Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Diaspore feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.65 for Quartz).
- They overlap in clear, gray, yellow, brown, pink, and purple, but Diaspore also comes in green and Quartz also comes in black.
- Well-formed crystals give it away: Diaspore is Orthorhombic, Quartz is Trigonal.
Diaspore vs Quartz properties
| Property | Diaspore | Quartz |
|---|---|---|
| Type | Minerals | Quartz Family |
| Mohs hardness | 6.5–7 | 7 |
| Luster | Vitreous to pearly on cleavage | Vitreous, greasy on fracture surfaces |
| Streak | White | White |
| Transparency | Transparent to translucent | Transparent to translucent |
| Specific gravity | 3.3–3.5 | 2.65 |
| Crystal system | Orthorhombic | Trigonal |
| Common colors | Colorless, White, Gray, Yellowish, Brown, Green, Violet-pink (color-change) | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $5–$250+ |
Which is more valuable?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $20 for Diaspore, and premium Quartz can reach $250 or more.
About Diaspore
Diaspore is aluminum oxide hydroxide, AlO(OH), a hard, dense mineral that forms in aluminum-rich metamorphic and hydrothermal environments and ranks among the principal minerals in bauxite ore. It is dimorphous with boehmite, sharing an identical chemical formula but a different crystal structure, and it characteristically splits apart with a sudden crackling sound when heated, a property that inspired its name. Transparent gem-quality crystals, sold as zultanite or csarite, display a striking color change from green to pink or champagne under different lighting.
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.
Diaspore vs Quartz FAQ
Is Diaspore the same as Quartz?
No. Diaspore is a mineral while Quartz is a quartz family. Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Diaspore from Quartz?
Both sit near Mohs 6.5–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Diaspore feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.65 for Quartz). They overlap in clear, gray, yellow, brown, pink, and purple, but Diaspore also comes in green and Quartz also comes in black.
Which is harder, Diaspore or Quartz?
They are about equally hard, both near Mohs 6.5–7.
Which is more valuable, Diaspore or Quartz?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $20 for Diaspore, and premium Quartz can reach $250 or more.
