Identification guide · Metals & Alloys
How to Identify Brass
Brass is usually yellow gold, brass yellow, and brown with a metallic luster and is opaque. It has a Mohs hardness of 3.5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is yellow-gold to brass. It is most often confused with Bronze, Zinc, and Copper; the tests below separate them.
Brass identification checklist
| Color | Yellow gold, Brass yellow, Brown, Tarnished gold | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Metallic | Turn it under a lamp: a true metallic shine reflects like polished metal and stays opaque at thin edges. |
| Transparency | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 3.5 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | Yellow-gold to brass | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Ductile to uneven | |
| Specific gravity | 8.5 | Very heavy, metallic heft (specific gravity about 8.5). |
Brass look-alikes and how to tell them apart
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Brass vs Bronze →
Brass is harder (Mohs 3.5) than Zinc (Mohs 2.5), so Brass will scratch Zinc and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Brass vs Zinc →
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Brass vs Copper →
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Brass vs Iron →
Field tips
- Look for a warm yellow-gold metal color.
- Brass is usually yellower than bronze and less orange-red than copper.
- Tarnished areas may appear brown, olive, or dull gold.
- Common objects include keys, fittings, screws, handles, and instruments.
Brass identification FAQ
How can you tell if a rock is Brass?
Check the color (yellow gold, brass yellow, brown, and tarnished gold), the metallic luster, a Mohs hardness of 3.5 and a yellow-gold to brass streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Brass?
Brass has a Mohs hardness of 3.5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Brass and Bronze?
Brass (Mohs 3.5, metallic luster) and Bronze (Mohs 3, metallic luster) look alike, but hardness, streak and heft usually separate them. See the full Brass vs Bronze comparison for a side-by-side table.
Is Brass worth anything?
Entry-level Brass specimens sell for around $1, typical collector pieces about $15, and premium examples $150 or more depending on size, quality and locality.
What color is Brass?
Brass is most often yellow gold, brass yellow, brown, and tarnished gold. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
