Comparison · Metamorphic Rocks vs Quartz Family
Marble vs Quartz
Marble and Quartz are easy to confuse. Quartz is harder (Mohs 7) than Marble (Mohs 3.5), so Quartz will scratch Marble 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 Marble and Quartz
- Quartz is harder (Mohs 7) than Marble (Mohs 3.5), so Quartz will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
- Hold a thin edge to the light: Marble is translucent, Quartz is Transparent to translucent.
- They overlap in gray, pink, and black, but Marble also comes in white and green and Quartz also comes in clear, purple, yellow, and brown.
Marble vs Quartz properties
| Property | Marble | Quartz |
|---|---|---|
| Type | Metamorphic Rocks | Quartz Family |
| Mohs hardness | 3.5 | 7 |
| Luster | vitreous | Vitreous, greasy on fracture surfaces |
| Streak | White | White |
| Transparency | translucent | Transparent to translucent |
| Specific gravity | 2.7 | 2.65 |
| Crystal system | varies | Trigonal |
| Common colors | White, Gray, Pink, Green, Black | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $5–$500+ | $5–$250+ |
Which is more valuable?
Marble is usually the more valuable of the two: a typical collector specimen runs about $50 against $35 for Quartz, and premium Marble can reach $500 or more.
About Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals. It has been used for sculpture and architecture since ancient times.
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.
Marble vs Quartz FAQ
Is Marble the same as Quartz?
No. Marble is a metamorphic rock while Quartz is a quartz family. Quartz is harder (Mohs 7) than Marble (Mohs 3.5), so Quartz will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
How can you tell Marble from Quartz?
Quartz is harder (Mohs 7) than Marble (Mohs 3.5), so Quartz will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Hold a thin edge to the light: Marble is translucent, Quartz is Transparent to translucent. They overlap in gray, pink, and black, but Marble also comes in white and green and Quartz also comes in clear, purple, yellow, and brown.
Which is harder, Marble or Quartz?
Quartz is harder: Mohs 7 against Mohs 3.5 for Marble.
Which is more valuable, Marble or Quartz?
Marble is usually the more valuable of the two: a typical collector specimen runs about $50 against $35 for Quartz, and premium Marble can reach $500 or more.
