Identification guide · Minerals
How to Identify Apatite
Apatite typically forms hexagonal prisms with flat terminations, though it also occurs massive or granular. Color spans colorless, green, blue, yellow, violet, and brown, with a vitreous to slightly resinous luster and a white streak. Its defining trait is a hardness of exactly 5, scratched easily by a steel knife blade yet resistant to a fingernail. Cleavage is poor and fracture is conchoidal to uneven. Apatite is frequently mistaken for beryl, tourmaline, or fluorite until a hardness test settles the question.
Apatite identification checklist
| Color | Green, Blue, Yellow, Violet, Colorless, Brown | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous to subresinous | 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 | 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 | Poor, basal and prismatic | |
| Fracture | Conchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 3.1–3.2 | Heavier than it looks (specific gravity about 3.1500000000000004). |
| Crystal system | Hexagonal |
Extra tests for Apatite
Glass check. Apatite 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.
Apatite look-alikes and how to tell them apart
Apatite is harder (Mohs 5) than Calcite (Mohs 3), so Apatite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Apatite vs Calcite →
Albite is harder (Mohs 6–6.5) than Apatite (Mohs 5), so Albite will scratch Apatite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Apatite vs Albite →
Both sit near Mohs 5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Apatite vs Apophyllite →
Apatite is harder (Mohs 5) than Aragonite (Mohs 3.5–4), so Apatite will scratch Aragonite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
Apatite identification FAQ
How can you tell if a rock is Apatite?
Check the color (green, blue, yellow, and violet), the vitreous to subresinous luster, a Mohs hardness of 5 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Apatite?
Apatite has a Mohs hardness of 5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Apatite and Calcite?
Apatite (Mohs 5, vitreous to subresinous luster) and Calcite (Mohs 3, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Apatite vs Calcite comparison for a side-by-side table.
Is Apatite worth anything?
Entry-level Apatite 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 Apatite?
Apatite is most often green, blue, yellow, and violet. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
