Comparison · Quartz Family
Milky Quartz vs Quartz
Milky Quartz and Quartz are easy to confuse because both are quartz family. 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 Milky Quartz and Quartz
- Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Milky Quartz is Translucent to nearly opaque, Quartz is Transparent to translucent.
Milky Quartz vs Quartz properties
| Property | Milky Quartz | Quartz |
|---|---|---|
| Type | Quartz Family | Quartz Family |
| Mohs hardness | 7 | 7 |
| Luster | Vitreous, greasy | Vitreous, greasy on fracture surfaces |
| Streak | White | White |
| Transparency | Translucent to nearly opaque | Transparent to translucent |
| Specific gravity | 2.65 | 2.65 |
| Crystal system | Trigonal | Trigonal |
| Common colors | Milky white, White | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $5–$250+ | $5–$250+ |
Which is more valuable?
Typical specimens of Milky Quartz and Quartz trade in a similar range, around $35.
About Milky Quartz
Milky quartz is the cloudy white to grayish-white variety of quartz, SiO2, its characteristic opacity caused by countless microscopic fluid inclusions and tiny gas bubbles trapped during crystal growth. It is the most common form of macrocrystalline quartz found in veins worldwide, forming wherever silica-saturated hydrothermal fluids cool and crystallize within fractures in host rock. Unlike clear rock crystal quartz, milky quartz's cloudiness comes specifically from these internal inclusions rather than from any difference in chemical composition.
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.
Milky Quartz vs Quartz FAQ
Is Milky Quartz the same as Quartz?
No. Both are quartz family, but they are distinct species with different hardness, streak or luster. 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 Milky Quartz from Quartz?
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Milky Quartz is Translucent to nearly opaque, Quartz is Transparent to translucent.
Which is harder, Milky Quartz or Quartz?
They are about equally hard, both near Mohs 7.
Which is more valuable, Milky Quartz or Quartz?
Typical specimens of Milky Quartz and Quartz trade in a similar range, around $35.
