Comparison · Igneous Rocks vs Quartz Family
Kimberlite vs Quartz
Kimberlite and Quartz are easy to confuse. Quartz is harder (Mohs 7) than Kimberlite (Mohs 5–6.5), so Quartz will scratch Kimberlite 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 Kimberlite and Quartz
- Quartz is harder (Mohs 7) than Kimberlite (Mohs 5–6.5), so Quartz will scratch Kimberlite 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.
- Hold a thin edge to the light: Kimberlite is Opaque, Quartz is Transparent to translucent.
- They overlap in gray and yellow, but Kimberlite also comes in blue and green and Quartz also comes in clear, purple, pink, black, and brown.
Kimberlite vs Quartz properties
| Property | Kimberlite | Quartz |
|---|---|---|
| Type | Igneous Rocks | Quartz Family |
| Mohs hardness | 5–6.5 | 7 |
| Luster | Dull to vitreous | Vitreous, greasy on fracture surfaces |
| Streak | — | White |
| Transparency | Opaque | Transparent to translucent |
| Specific gravity | 2.5–2.9 | 2.65 |
| Crystal system | — | Trigonal |
| Common colors | Blue-gray ('blue ground'), Yellow ('yellow ground', weathered), Dark green, Gray | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $5–$250+ |
Which is more valuable?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $10 for Kimberlite, and premium Quartz can reach $250 or more.
About Kimberlite
Kimberlite is a rare, ultramafic igneous rock famous as the primary source rock for natural diamonds. It originates from partial melting deep in Earth's mantle, often more than one hundred fifty kilometers down, and erupts violently through narrow, carrot-shaped volcanic pipes. Named after Kimberley, South Africa, where major diamond-bearing pipes were first mined, it is a chaotic mixture of olivine, mica, and fragments picked up from surrounding rock on its way to the surface.
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.
Kimberlite vs Quartz FAQ
Is Kimberlite the same as Quartz?
No. Kimberlite is a igneous rock while Quartz is a quartz family. Quartz is harder (Mohs 7) than Kimberlite (Mohs 5–6.5), so Quartz will scratch Kimberlite 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 Kimberlite from Quartz?
Quartz is harder (Mohs 7) than Kimberlite (Mohs 5–6.5), so Quartz will scratch Kimberlite 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. Hold a thin edge to the light: Kimberlite is Opaque, Quartz is Transparent to translucent. They overlap in gray and yellow, but Kimberlite also comes in blue and green and Quartz also comes in clear, purple, pink, black, and brown.
Which is harder, Kimberlite or Quartz?
Quartz is harder: Mohs 7 against Mohs 5–6.5 for Kimberlite.
Which is more valuable, Kimberlite or Quartz?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $10 for Kimberlite, and premium Quartz can reach $250 or more.
