Comparison · Minerals vs Sulfide Minerals
Cinnabar vs Stibnite
Cinnabar and Stibnite are easy to confuse. Both sit near Mohs 2–2.5, 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 Cinnabar and Stibnite
- Both sit near Mohs 2–2.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Cinnabar leaves a scarlet red streak on unglazed porcelain, Stibnite leaves lead gray.
- Luster is different: Cinnabar is adamantine to dull/earthy while Stibnite is metallic.
- Cinnabar feels noticeably heavier for its size (specific gravity 8.0–8.2 versus 4.6 for Stibnite).
- Hold a thin edge to the light: Cinnabar is Transparent to opaque, Stibnite is opaque.
- They overlap in gray, but Cinnabar also comes in red and brown.
- Well-formed crystals give it away: Cinnabar is Trigonal, Stibnite is orthorhombic.
Cinnabar vs Stibnite properties
| Property | Cinnabar | Stibnite |
|---|---|---|
| Type | Minerals | Sulfide Minerals |
| Mohs hardness | 2–2.5 | 2 |
| Luster | Adamantine to dull/earthy | metallic |
| Streak | Scarlet red | Lead gray |
| Transparency | Transparent to opaque | opaque |
| Specific gravity | 8.0–8.2 | 4.6 |
| Crystal system | Trigonal | orthorhombic |
| Common colors | Red, Brownish red, Gray where tarnished | Lead gray, Steel gray, Silvery gray |
| Rarity | common | uncommon |
| Typical specimen value | $2–$150+ | $10–$1500+ |
Which is more valuable?
Stibnite is usually the more valuable of the two: a typical collector specimen runs about $120 against $20 for Cinnabar, and premium Stibnite can reach $1500 or more.
About Cinnabar
Cinnabar is mercury sulfide, HgS, the principal ore mineral of mercury and one of the most historically significant toxic minerals in human history. It forms a brilliant red to brownish-red mineral typically deposited by low-temperature hydrothermal fluids near volcanic activity and hot springs, often associated with recent or geologically young volcanic terrains. Cinnabar has been mined for millennia both for its metal content and, historically and dangerously, as a pigment source.
About Stibnite
Stibnite is antimony sulfide, the chief ore of antimony. It is famous for brilliant steel-gray metallic crystals that form long, slender, often curved or radiating prismatic blades with perfect lengthwise cleavage.
Cinnabar vs Stibnite FAQ
Is Cinnabar the same as Stibnite?
No. Cinnabar is a mineral while Stibnite is a sulfide mineral. Both sit near Mohs 2–2.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Cinnabar from Stibnite?
Both sit near Mohs 2–2.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Cinnabar leaves a scarlet red streak on unglazed porcelain, Stibnite leaves lead gray. Luster is different: Cinnabar is adamantine to dull/earthy while Stibnite is metallic.
Which is harder, Cinnabar or Stibnite?
They are about equally hard, both near Mohs 2–2.5.
Which is more valuable, Cinnabar or Stibnite?
Stibnite is usually the more valuable of the two: a typical collector specimen runs about $120 against $20 for Cinnabar, and premium Stibnite can reach $1500 or more.
