Identification guide · Minerals
How to Identify Cassiterite
Cassiterite shows reddish-brown, black, or occasionally yellow prismatic to pyramidal crystals with an adamantine to submetallic luster, quite unlike a typical dull ore mineral. Streak is white to pale brown, hardness is 6 to 7, and there is no cleavage of note, only an uneven to subconchoidal fracture. Its unusually high heft for a nonmetallic-looking mineral is a strong field clue, and elbow-shaped twin crystals are common. It can resemble tourmaline or sphalerite, but neither matches its density.
Cassiterite identification checklist
| Color | Brown, Black, Reddish brown, Yellow, Gray | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Adamantine to submetallic | Turn it under a lamp: a true metallic shine reflects like polished metal and stays opaque at thin edges. |
| Transparency | Translucent to opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6–7 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | White to grayish brown | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Imperfect prismatic | |
| Fracture | Conchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 6.8–7.1 | Very heavy, metallic heft (specific gravity about 6.949999999999999). |
| Crystal system | Tetragonal |
Cassiterite look-alikes and how to tell them apart
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Cassiterite vs Hematite →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Cassiterite vs Quartz →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Cassiterite vs Onyx →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Cassiterite identification FAQ
How can you tell if a rock is Cassiterite?
Check the color (brown, black, reddish brown, and yellow), the adamantine to submetallic luster, a Mohs hardness of 6–7 and a white to grayish brown streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Cassiterite?
Cassiterite has a Mohs hardness of 6–7. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Cassiterite and Hematite?
Cassiterite (Mohs 6–7, adamantine to submetallic luster) and Hematite (Mohs 6, metallic luster) look alike, but hardness, streak and heft usually separate them. See the full Cassiterite vs Hematite comparison for a side-by-side table.
Is Cassiterite worth anything?
Entry-level Cassiterite specimens sell for around $2, typical collector pieces about $20, and premium examples $150 or more depending on size, quality and locality.
What color is Cassiterite?
Cassiterite is most often brown, black, reddish brown, and yellow. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
