Comparison · Minerals vs Silicate Minerals
Aragonite vs Natrolite
Aragonite and Natrolite are easy to confuse. Natrolite is harder (Mohs 5.5) than Aragonite (Mohs 3.5–4), so Natrolite will scratch Aragonite 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 Aragonite and Natrolite
- Natrolite is harder (Mohs 5.5) than Aragonite (Mohs 3.5–4), so Natrolite will scratch Aragonite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
- Aragonite feels noticeably heavier for its size (specific gravity 2.93–2.95 versus 2.25 for Natrolite).
- Hold a thin edge to the light: Aragonite is Transparent to translucent, Natrolite is transparent.
- They overlap in clear, yellow, gray, and pink, but Aragonite also comes in blue.
- Well-formed crystals give it away: Aragonite is Orthorhombic, Natrolite is orthorhombic.
Aragonite vs Natrolite properties
| Property | Aragonite | Natrolite |
|---|---|---|
| Type | Minerals | Silicate Minerals |
| Mohs hardness | 3.5–4 | 5.5 |
| Luster | Vitreous to resinous | vitreous |
| Streak | White | White |
| Transparency | Transparent to translucent | transparent |
| Specific gravity | 2.93–2.95 | 2.25 |
| Crystal system | Orthorhombic | orthorhombic |
| Common colors | Colorless, White, Yellow, Gray, Blue, Pink | Colorless, White, Pink, Yellow, Gray |
| Rarity | common | uncommon |
| Typical specimen value | $2–$150+ | $8–$250+ |
Which is more valuable?
Natrolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $20 for Aragonite, and premium Natrolite can reach $250 or more.
About Aragonite
Aragonite is calcium carbonate, CaCO3, crystallizing in the orthorhombic system as a metastable polymorph of the more common mineral calcite. It readily forms in low-temperature settings such as caves, hot springs, and the shells of many marine organisms, and it slowly converts to calcite over geologic time. Twinned crystal clusters resembling six-rayed stars are among its most recognizable forms.
About Natrolite
Natrolite is a sodium-rich zeolite mineral that forms delicate, slender prismatic crystals, often gathered into radiating sprays. It typically occurs in cavities of basalt and is valued by collectors for its needle-like sprays.
Aragonite vs Natrolite FAQ
Is Aragonite the same as Natrolite?
No. Aragonite is a mineral while Natrolite is a silicate mineral. Natrolite is harder (Mohs 5.5) than Aragonite (Mohs 3.5–4), so Natrolite will scratch Aragonite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
How can you tell Aragonite from Natrolite?
Natrolite is harder (Mohs 5.5) than Aragonite (Mohs 3.5–4), so Natrolite will scratch Aragonite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Aragonite feels noticeably heavier for its size (specific gravity 2.93–2.95 versus 2.25 for Natrolite). Hold a thin edge to the light: Aragonite is Transparent to translucent, Natrolite is transparent.
Which is harder, Aragonite or Natrolite?
Natrolite is harder: Mohs 5.5 against Mohs 3.5–4 for Aragonite.
Which is more valuable, Aragonite or Natrolite?
Natrolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $20 for Aragonite, and premium Natrolite can reach $250 or more.
