Comparison · Minerals vs Silicate Minerals
Calcite vs Stilbite
Calcite and Stilbite are easy to confuse. Both sit near Mohs 3, 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 Calcite and Stilbite
- Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Calcite feels noticeably heavier for its size (specific gravity 2.7 versus 2.2 for Stilbite).
- They overlap in yellow and pink, but Calcite also comes in clear, orange, blue, and green and Stilbite also comes in white and brown.
- Well-formed crystals give it away: Calcite is trigonal, Stilbite is monoclinic.
Calcite vs Stilbite properties
| Property | Calcite | Stilbite |
|---|---|---|
| Type | Minerals | Silicate Minerals |
| Mohs hardness | 3 | 3.75 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | transparent | transparent |
| Specific gravity | 2.7 | 2.2 |
| Crystal system | trigonal | monoclinic |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | White, Pink, Salmon, Yellow, Brown |
| Rarity | common | common |
| Typical specimen value | $2–$100+ | $5–$250+ |
Which is more valuable?
Stilbite is usually the more valuable of the two: a typical collector specimen runs about $40 against $15 for Calcite, and premium Stilbite can reach $250 or more.
About Calcite
Calcite is one of the most common minerals on Earth, found in sedimentary, metamorphic, and igneous rocks. It's the primary component of limestone and marble.
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.
Calcite vs Stilbite FAQ
Is Calcite the same as Stilbite?
No. Calcite is a mineral while Stilbite is a silicate mineral. Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Calcite from Stilbite?
Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Calcite feels noticeably heavier for its size (specific gravity 2.7 versus 2.2 for Stilbite). They overlap in yellow and pink, but Calcite also comes in clear, orange, blue, and green and Stilbite also comes in white and brown.
Which is harder, Calcite or Stilbite?
Stilbite is harder: Mohs 3.75 against Mohs 3 for Calcite.
Which is more valuable, Calcite or Stilbite?
Stilbite is usually the more valuable of the two: a typical collector specimen runs about $40 against $15 for Calcite, and premium Stilbite can reach $250 or more.
