Comparison · Quartz Family
Amethyst vs Quartz
Amethyst 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 Amethyst 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: Amethyst is transparent, Quartz is Transparent to translucent.
- They overlap in purple, but Quartz also comes in clear, yellow, pink, black, gray, and brown.
- Well-formed crystals give it away: Amethyst is hexagonal, Quartz is Trigonal.
Amethyst vs Quartz properties
| Property | Amethyst | Quartz |
|---|---|---|
| Type | Quartz Family | Quartz Family |
| Mohs hardness | 7 | 7 |
| Luster | vitreous | Vitreous, greasy on fracture surfaces |
| Streak | White | White |
| Transparency | transparent | Transparent to translucent |
| Specific gravity | 2.65 | 2.65 |
| Crystal system | hexagonal | Trigonal |
| Common colors | Purple, Violet, Deep Purple, Lavender | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $10–$500+ | $5–$250+ |
Which is more valuable?
Amethyst is usually the more valuable of the two: a typical collector specimen runs about $50 against $35 for Quartz, and premium Amethyst can reach $500 or more.
About Amethyst
Amethyst is a purple variety of quartz and is the traditional birthstone for February. It's prized for its beautiful purple color ranging from light lavender to deep violet.
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.
Amethyst vs Quartz FAQ
Is Amethyst 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 Amethyst 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: Amethyst is transparent, Quartz is Transparent to translucent. They overlap in purple, but Quartz also comes in clear, yellow, pink, black, gray, and brown.
Which is harder, Amethyst or Quartz?
They are about equally hard, both near Mohs 7.
Which is more valuable, Amethyst or Quartz?
Amethyst is usually the more valuable of the two: a typical collector specimen runs about $50 against $35 for Quartz, and premium Amethyst can reach $500 or more.
