Identification guide · Arsenate Minerals
How to Identify Mimetite
Mimetite is usually yellow, orange, and yellow-brown with a resinous luster and is translucent. It has a Mohs hardness of 3.75. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is white. It is most often confused with Pyromorphite, Wulfenite, and Phlogopite; the tests below separate them.
Mimetite identification checklist
| Color | Yellow, Orange, Yellow-brown, Pale green, White | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Resinous | Compare a fresh surface with glass and metal; this luster is softer than either. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 3.75 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Subconchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 7.24 | Very heavy, metallic heft (specific gravity about 7.24). |
| Crystal system | Hexagonal |
Mimetite look-alikes and how to tell them apart
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Mimetite vs Pyromorphite →
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Mimetite vs Wulfenite →
Mimetite is harder (Mohs 3.75) than Phlogopite (Mohs 2.75), so Mimetite will scratch Phlogopite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Mimetite vs Phlogopite →
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Mimetite vs Serpentine →
Field tips
- Look for warm yellow to orange botryoidal crusts or barrel-shaped hexagonal crystals with a resinous luster.
- Mimetite is heavy for its size due to lead and is fairly soft at about 3.5 to 4 in hardness.
- It is nearly impossible to distinguish from pyromorphite by eye; chemical testing confirms the arsenic content.
Mimetite identification FAQ
How can you tell if a rock is Mimetite?
Check the color (yellow, orange, yellow-brown, and pale green), the resinous luster, a Mohs hardness of 3.75 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Mimetite?
Mimetite has a Mohs hardness of 3.75. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Mimetite and Pyromorphite?
Mimetite (Mohs 3.75, resinous luster) and Pyromorphite (Mohs 3.75, resinous luster) look alike, but hardness, streak and heft usually separate them. See the full Mimetite vs Pyromorphite comparison for a side-by-side table.
Is Mimetite worth anything?
Entry-level Mimetite specimens sell for around $15, typical collector pieces about $90, and premium examples $600 or more depending on size, quality and locality.
What color is Mimetite?
Mimetite is most often yellow, orange, yellow-brown, and pale green. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
