Comparison · Minerals
Cinnabar vs Cuprite
Cinnabar and Cuprite are easy to confuse because both are minerals. Cuprite is harder (Mohs 3.5–4) than Cinnabar (Mohs 2–2.5), so Cuprite will scratch Cinnabar and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Cinnabar and Cuprite
- Cuprite is harder (Mohs 3.5–4) than Cinnabar (Mohs 2–2.5), so Cuprite will scratch Cinnabar and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
- Streak color differs: Cinnabar leaves a scarlet red streak on unglazed porcelain, Cuprite leaves brownish red.
- Luster is different: Cinnabar is adamantine to dull/earthy while Cuprite is adamantine to submetallic or earthy.
- Cinnabar feels noticeably heavier for its size (specific gravity 8.0–8.2 versus 6.0–6.15 for Cuprite).
- Hold a thin edge to the light: Cinnabar is Transparent to opaque, Cuprite is Transparent to nearly opaque.
- They overlap in red, but Cinnabar also comes in brown and gray and Cuprite also comes in black.
- Well-formed crystals give it away: Cinnabar is Trigonal, Cuprite is Cubic.
Cinnabar vs Cuprite properties
| Property | Cinnabar | Cuprite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 2–2.5 | 3.5–4 |
| Luster | Adamantine to dull/earthy | Adamantine to submetallic or earthy |
| Streak | Scarlet red | Brownish red |
| Transparency | Transparent to opaque | Transparent to nearly opaque |
| Specific gravity | 8.0–8.2 | 6.0–6.15 |
| Crystal system | Trigonal | Cubic |
| Common colors | Red, Brownish red, Gray where tarnished | Red, Dark red, Nearly black |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Cinnabar and Cuprite trade in a similar range, around $20.
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 Cuprite
Cuprite is a copper oxide mineral, Cu2O, notable for its deep red color and status as an important secondary ore of copper. It forms in the oxidized upper zones of copper sulfide deposits, where weathering converts primary copper minerals into oxides and carbonates. Cuprite often occurs alongside native copper, malachite, and azurite, forming a colorful assemblage typical of copper deposit gossans.
Cinnabar vs Cuprite FAQ
Is Cinnabar the same as Cuprite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Cuprite is harder (Mohs 3.5–4) than Cinnabar (Mohs 2–2.5), so Cuprite will scratch Cinnabar and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Cinnabar from Cuprite?
Cuprite is harder (Mohs 3.5–4) than Cinnabar (Mohs 2–2.5), so Cuprite will scratch Cinnabar and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Streak color differs: Cinnabar leaves a scarlet red streak on unglazed porcelain, Cuprite leaves brownish red. Luster is different: Cinnabar is adamantine to dull/earthy while Cuprite is adamantine to submetallic or earthy.
Which is harder, Cinnabar or Cuprite?
Cuprite is harder: Mohs 3.5–4 against Mohs 2–2.5 for Cinnabar.
Which is more valuable, Cinnabar or Cuprite?
Typical specimens of Cinnabar and Cuprite trade in a similar range, around $20.
