Comparison · Quartz Family vs Sedimentary Rocks
Quartz vs Sandstone
Quartz and Sandstone are easy to confuse. Quartz is harder (Mohs 7) than Sandstone (Mohs 6), so Quartz will scratch Sandstone 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 Quartz and Sandstone
- Quartz is harder (Mohs 7) than Sandstone (Mohs 6), so Quartz will scratch Sandstone 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.
- Streak color differs: Quartz leaves a white streak on unglazed porcelain, Sandstone leaves variable; test individual minerals.
- Luster is different: Quartz is vitreous, greasy on fracture surfaces while Sandstone is dull.
- Hold a thin edge to the light: Quartz is Transparent to translucent, Sandstone is opaque.
- They overlap in yellow, gray, and brown, but Quartz also comes in clear, purple, pink, and black and Sandstone also comes in red and white.
Quartz vs Sandstone properties
| Property | Quartz | Sandstone |
|---|---|---|
| Type | Quartz Family | Sedimentary Rocks |
| Mohs hardness | 7 | 6 |
| Luster | Vitreous, greasy on fracture surfaces | dull |
| Streak | White | Variable; test individual minerals |
| Transparency | Transparent to translucent | opaque |
| Specific gravity | 2.65 | 2.3 |
| Crystal system | Trigonal | varies |
| Common colors | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) | Tan, Brown, Red, Yellow, White, Gray |
| Rarity | common | common |
| Typical specimen value | $5–$250+ | $1–$100+ |
Which is more valuable?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $15 for Sandstone, and premium Quartz can reach $250 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 Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized mineral particles or rock fragments. Color varies based on mineral content and cementing material.
Quartz vs Sandstone FAQ
Is Quartz the same as Sandstone?
No. Quartz is a quartz family while Sandstone is a sedimentary rock. Quartz is harder (Mohs 7) than Sandstone (Mohs 6), so Quartz will scratch Sandstone 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 Quartz from Sandstone?
Quartz is harder (Mohs 7) than Sandstone (Mohs 6), so Quartz will scratch Sandstone 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. Streak color differs: Quartz leaves a white streak on unglazed porcelain, Sandstone leaves variable; test individual minerals. Luster is different: Quartz is vitreous, greasy on fracture surfaces while Sandstone is dull.
Which is harder, Quartz or Sandstone?
Quartz is harder: Mohs 7 against Mohs 6 for Sandstone.
Which is more valuable, Quartz or Sandstone?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $15 for Sandstone, and premium Quartz can reach $250 or more.
