Comparison · Minerals vs Silicate Minerals
Heulandite vs Stilbite
Heulandite and Stilbite are easy to confuse. Both sit near Mohs 3.5–4, 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 Heulandite and Stilbite
- Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Heulandite is Transparent to translucent, Stilbite is transparent.
- They overlap in pink, brown, and yellow, but Heulandite also comes in clear and red and Stilbite also comes in white.
- Well-formed crystals give it away: Heulandite is Monoclinic, Stilbite is monoclinic.
Heulandite vs Stilbite properties
| Property | Heulandite | Stilbite |
|---|---|---|
| Type | Minerals | Silicate Minerals |
| Mohs hardness | 3.5–4 | 3.75 |
| Luster | Vitreous, pearly on cleavage | vitreous |
| Streak | White | White |
| Transparency | Transparent to translucent | transparent |
| Specific gravity | 2.1–2.2 | 2.2 |
| Crystal system | Monoclinic | monoclinic |
| Common colors | White, Colorless, Pink, Red, Brown, Yellow | White, Pink, Salmon, Yellow, Brown |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $5–$250+ |
Which is more valuable?
Stilbite is usually the more valuable of the two: a typical collector specimen runs about $40 against $20 for Heulandite, and premium Stilbite can reach $250 or more.
About Heulandite
Heulandite is a calcium- and sodium-bearing zeolite mineral, part of a group known for its coffin-shaped monoclinic crystals with a distinctive pearly luster on one prominent cleavage face. It typically forms as a secondary mineral filling vesicles and fractures in basaltic and volcanic rocks, alongside other zeolites deposited by cooling hydrothermal fluids. Heulandite is named after English mineral collector Henry Heuland, whose collection contributed significantly to early zeolite mineralogy.
About Stilbite
Stilbite is a calcium-rich zeolite mineral known for its distinctive sheaf-like or bowtie-shaped crystal aggregates. It commonly occurs as white to salmon-pink crystals lining cavities in basalt, often with other zeolites.
Heulandite vs Stilbite FAQ
Is Heulandite the same as Stilbite?
No. Heulandite is a mineral while Stilbite is a silicate mineral. Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Heulandite from Stilbite?
Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Heulandite is Transparent to translucent, Stilbite is transparent. They overlap in pink, brown, and yellow, but Heulandite also comes in clear and red and Stilbite also comes in white.
Which is harder, Heulandite or Stilbite?
They are about equally hard, both near Mohs 3.5–4.
Which is more valuable, Heulandite or Stilbite?
Stilbite is usually the more valuable of the two: a typical collector specimen runs about $40 against $20 for Heulandite, and premium Stilbite can reach $250 or more.
