Identification guide · Oxide Minerals
How to Identify Rutile
Rutile is usually reddish brown, black, and golden yellow with a adamantine luster and is translucent. It has a Mohs hardness of 6.5. It scratches glass and a steel knife and cannot be scratched by a steel file. Its streak is pale brown to yellowish. It is most often confused with Quartz, Ilmenite, and Staurolite; the tests below separate them.
Rutile identification checklist
| Color | Reddish brown, Black, Golden yellow, Red | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Adamantine | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6.5 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | Pale brown to yellowish | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Good on {110} | |
| Fracture | Conchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 4.25 | Heavier than it looks (specific gravity about 4.25). |
| Crystal system | Tetragonal |
Rutile look-alikes and how to tell them apart
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Rutile vs Quartz →
Rutile is harder (Mohs 6.5) than Ilmenite (Mohs 5.5), so Rutile will scratch Ilmenite 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. Rutile vs Ilmenite →
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Rutile vs Staurolite →
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Field tips
- Look for very high adamantine luster, reddish-brown to black color, and slender striated prismatic crystals.
- Distinctive knee-shaped or heart-shaped twins are common and help confirm rutile.
- Golden needle inclusions in clear quartz are a strong indicator of rutilated quartz.
Rutile identification FAQ
How can you tell if a rock is Rutile?
Check the color (reddish brown, black, golden yellow, and red), the adamantine luster, a Mohs hardness of 6.5 and a pale brown to yellowish streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Rutile?
Rutile has a Mohs hardness of 6.5. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Rutile and Quartz?
Rutile (Mohs 6.5, adamantine luster) and Quartz (Mohs 7, vitreous, greasy on fracture surfaces luster) look alike, but hardness, streak and heft usually separate them. See the full Rutile vs Quartz comparison for a side-by-side table.
Is Rutile worth anything?
Entry-level Rutile specimens sell for around $10, typical collector pieces about $80, and premium examples $600 or more depending on size, quality and locality.
What color is Rutile?
Rutile is most often reddish brown, black, golden yellow, and red. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
