Comparison · Minerals
Cassiterite vs Magnetite
Cassiterite and Magnetite are easy to confuse because both are minerals. Both sit near Mohs 6–7, 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 Cassiterite and Magnetite
- Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Cassiterite leaves a white to grayish brown streak on unglazed porcelain, Magnetite leaves 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 5.17–5.2 for Magnetite).
- Hold a thin edge to the light: Cassiterite is Translucent to opaque, Magnetite is Opaque.
- They overlap in black and gray, but Cassiterite also comes in brown, red, and yellow.
- Well-formed crystals give it away: Cassiterite is Tetragonal, Magnetite is Cubic.
Cassiterite vs Magnetite properties
| Property | Cassiterite | Magnetite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 6–7 | 5.5–6.5 |
| Luster | Adamantine to submetallic | Metallic to submetallic/dull |
| Streak | White to grayish brown | Black |
| Transparency | Translucent to opaque | Opaque |
| Specific gravity | 6.8–7.1 | 5.17–5.2 |
| Crystal system | Tetragonal | Cubic |
| Common colors | Brown, Black, Reddish brown, Yellow, Gray | Black, Iron-black, Gray-black |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Cassiterite and Magnetite 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 Magnetite
Magnetite is an iron oxide mineral, Fe3O4, crystallizing in the cubic system and the most strongly magnetic naturally occurring mineral on Earth, capable of attracting steel objects and even acting as a natural compass in its lodestone form. It forms in a remarkably wide range of igneous, metamorphic, and sedimentary environments, making it one of the most common accessory minerals in rock-forming systems worldwide. Ancient sailors and travelers used naturally magnetized lodestone, a variety of magnetite, as the earliest known compasses.
Cassiterite vs Magnetite FAQ
Is Cassiterite the same as Magnetite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Cassiterite from Magnetite?
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Cassiterite leaves a white to grayish brown streak on unglazed porcelain, Magnetite leaves black. Both look metallic, so compare color, tarnish and weight rather than shine.
Which is harder, Cassiterite or Magnetite?
Cassiterite is harder: Mohs 6–7 against Mohs 5.5–6.5 for Magnetite.
Which is more valuable, Cassiterite or Magnetite?
Typical specimens of Cassiterite and Magnetite trade in a similar range, around $20.
