Comparison · Silicate Minerals
Nepheline vs Prehnite
Nepheline and Prehnite are easy to confuse because both are silicate minerals. Both sit near Mohs 6, 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 Nepheline and Prehnite
- Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- They overlap in gray, yellow, and green, but Nepheline also comes in clear and red and Prehnite also comes in white.
- Well-formed crystals give it away: Nepheline is hexagonal, Prehnite is orthorhombic.
Nepheline vs Prehnite properties
| Property | Nepheline | Prehnite |
|---|---|---|
| Type | Silicate Minerals | Silicate Minerals |
| Mohs hardness | 6 | 6.25 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | translucent | translucent |
| Specific gravity | 2.6 | 2.88 |
| Crystal system | hexagonal | orthorhombic |
| Common colors | Colorless, White, Gray, Yellowish, Greenish, Reddish | Green, Yellow-green, Yellow, White, Gray |
| Rarity | uncommon | uncommon |
| Typical specimen value | $5–$150+ | $10–$400+ |
Which is more valuable?
Prehnite is usually the more valuable of the two: a typical collector specimen runs about $70 against $30 for Nepheline, and premium Prehnite can reach $400 or more.
About Nepheline
Nepheline is a sodium and potassium aluminosilicate of the feldspathoid group, found in silica-poor igneous rocks. It usually appears as gray, greasy-looking masses and grains rather than well-formed crystals.
About Prehnite
Prehnite is a calcium aluminum silicate best known for its soft green to yellow-green color and rounded, botryoidal crystal aggregates. It commonly lines cavities in basalt and is valued by collectors and lapidaries for its translucent glow.
Nepheline vs Prehnite FAQ
Is Nepheline the same as Prehnite?
No. Both are silicate minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Nepheline from Prehnite?
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. They overlap in gray, yellow, and green, but Nepheline also comes in clear and red and Prehnite also comes in white. Well-formed crystals give it away: Nepheline is hexagonal, Prehnite is orthorhombic.
Which is harder, Nepheline or Prehnite?
They are about equally hard, both near Mohs 6.
Which is more valuable, Nepheline or Prehnite?
Prehnite is usually the more valuable of the two: a typical collector specimen runs about $70 against $30 for Nepheline, and premium Prehnite can reach $400 or more.
