Identification guide · Minerals
How to Identify Hemimorphite
Hemimorphite forms thin, bladed, fan-shaped crystals or botryoidal crusts, typically colorless, white, pale blue, or greenish, with a vitreous to silky luster. Its streak is white, hardness is about 4.5 to 5, and it shows distinct cleavage in one direction, though this is often hard to observe in the fine crystal sprays typical of the mineral. It reacts to acid much more slowly than the carbonate mineral smithsonite, which it closely resembles, making a dilute acid test the most reliable way to separate the two secondary zinc minerals in hand specimen.
Hemimorphite identification checklist
| Color | White, Colorless, Pale blue, Green, Brown, Yellowish | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous, silky when fibrous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Transparent to translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 4.5–5 | 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 | Perfect on {110} | |
| Fracture | Uneven to conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 3.4–3.5 | Heavier than it looks (specific gravity about 3.45). |
| Crystal system | Orthorhombic |
Extra tests for Hemimorphite
Glass check. Hemimorphite shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Hemimorphite look-alikes and how to tell them apart
Hemimorphite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Hemimorphite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Hemimorphite vs Calcite →
Albite is harder (Mohs 6–6.5) than Hemimorphite (Mohs 4.5–5), so Albite will scratch Hemimorphite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Hemimorphite vs Albite →
Both sit near Mohs 4.5–5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hemimorphite vs Apatite →
Both sit near Mohs 4.5–5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Hemimorphite identification FAQ
How can you tell if a rock is Hemimorphite?
Check the color (white, colorless, pale blue, and green), the vitreous, silky when fibrous luster, a Mohs hardness of 4.5–5 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Hemimorphite?
Hemimorphite has a Mohs hardness of 4.5–5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Hemimorphite and Calcite?
Hemimorphite (Mohs 4.5–5, vitreous, silky when fibrous luster) and Calcite (Mohs 3, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Hemimorphite vs Calcite comparison for a side-by-side table.
Is Hemimorphite worth anything?
Entry-level Hemimorphite 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 Hemimorphite?
Hemimorphite is most often white, colorless, pale blue, and green. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
