Comparison · Minerals
Cassiterite vs Chromite
Cassiterite and Chromite are easy to confuse because both are minerals. Cassiterite is harder (Mohs 6–7) than Chromite (Mohs 5.5), so Cassiterite will scratch Chromite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Cassiterite and Chromite
- Cassiterite is harder (Mohs 6–7) than Chromite (Mohs 5.5), so Cassiterite will scratch Chromite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
- Streak color differs: Cassiterite leaves a white to grayish brown streak on unglazed porcelain, Chromite leaves dark brown to black.
- Both look metallic, so compare color, tarnish and weight rather than shine.
- Cassiterite feels noticeably heavier for its size (specific gravity 6.8–7.1 versus 4.5–4.8 for Chromite).
- Hold a thin edge to the light: Cassiterite is Translucent to opaque, Chromite is Opaque.
- They overlap in brown and black, but Cassiterite also comes in red, yellow, and gray.
- Well-formed crystals give it away: Cassiterite is Tetragonal, Chromite is Isometric.
Cassiterite vs Chromite properties
| Property | Cassiterite | Chromite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 6–7 | 5.5 |
| Luster | Adamantine to submetallic | Metallic to submetallic |
| Streak | White to grayish brown | Dark brown to black |
| Transparency | Translucent to opaque | Opaque |
| Specific gravity | 6.8–7.1 | 4.5–4.8 |
| Crystal system | Tetragonal | Isometric |
| Common colors | Brown, Black, Reddish brown, Yellow, Gray | Black, Brownish black |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Cassiterite and Chromite trade in a similar range, around $20.
About Cassiterite
Cassiterite is tin oxide, SnO2, and has been the principal ore of tin since the Bronze Age. It crystallizes in the tetragonal system, typically as reddish-brown to black prismatic or pyramidal crystals with an adamantine luster and exceptionally high density for a nonmetallic-looking mineral. Its resistance to weathering means it survives erosion intact and concentrates in stream gravels as placer tin.
About Chromite
Chromite is iron chromium oxide, FeCr2O4, a member of the spinel group and the only economically significant ore of chromium. It crystallizes in the cubic system as black to brownish-black grains or octahedral crystals, most often found disseminated through dark, dense mafic and ultramafic rocks. Its formation is closely tied to the early crystallization of magma in large layered igneous intrusions.
Cassiterite vs Chromite FAQ
Is Cassiterite the same as Chromite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Cassiterite is harder (Mohs 6–7) than Chromite (Mohs 5.5), so Cassiterite will scratch Chromite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
How can you tell Cassiterite from Chromite?
Cassiterite is harder (Mohs 6–7) than Chromite (Mohs 5.5), so Cassiterite will scratch Chromite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Streak color differs: Cassiterite leaves a white to grayish brown streak on unglazed porcelain, Chromite leaves dark brown to black. Both look metallic, so compare color, tarnish and weight rather than shine.
Which is harder, Cassiterite or Chromite?
Cassiterite is harder: Mohs 6–7 against Mohs 5.5 for Chromite.
Which is more valuable, Cassiterite or Chromite?
Typical specimens of Cassiterite and Chromite trade in a similar range, around $20.
