Comparison · Quartz Family vs Silicate Minerals
Quartz vs Staurolite
Quartz and Staurolite are easy to confuse. Both sit near Mohs 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 Quartz and Staurolite
- Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Quartz leaves a white streak on unglazed porcelain, Staurolite leaves white to grayish.
- Staurolite feels noticeably heavier for its size (specific gravity 3.7 versus 2.65 for Quartz).
- Hold a thin edge to the light: Quartz is Transparent to translucent, Staurolite is translucent.
- They overlap in black and brown, but Quartz also comes in clear, purple, yellow, pink, and gray and Staurolite also comes in red.
- Well-formed crystals give it away: Quartz is Trigonal, Staurolite is monoclinic.
Quartz vs Staurolite properties
| Property | Quartz | Staurolite |
|---|---|---|
| Type | Quartz Family | Silicate Minerals |
| Mohs hardness | 7 | 7.25 |
| Luster | Vitreous, greasy on fracture surfaces | vitreous |
| Streak | White | White to grayish |
| Transparency | Transparent to translucent | translucent |
| Specific gravity | 2.65 | 3.7 |
| Crystal system | Trigonal | monoclinic |
| Common colors | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) | Reddish brown, Brown, Dark brown, Black |
| Rarity | common | uncommon |
| Typical specimen value | $5–$250+ | $5–$300+ |
Which is more valuable?
Staurolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $35 for Quartz, and premium Staurolite can reach $300 or more.
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.
About Staurolite
Staurolite is an iron aluminum silicate famous for its cross-shaped twinned crystals. It forms reddish-brown to nearly black prismatic crystals in metamorphic schists and is a classic index mineral of medium-grade metamorphism.
Quartz vs Staurolite FAQ
Is Quartz the same as Staurolite?
No. Quartz is a quartz family while Staurolite is a silicate mineral. Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Quartz from Staurolite?
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Quartz leaves a white streak on unglazed porcelain, Staurolite leaves white to grayish. Staurolite feels noticeably heavier for its size (specific gravity 3.7 versus 2.65 for Quartz).
Which is harder, Quartz or Staurolite?
They are about equally hard, both near Mohs 7.
Which is more valuable, Quartz or Staurolite?
Staurolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $35 for Quartz, and premium Staurolite can reach $300 or more.
