Identification guide · Minerals
How to Identify Apophyllite
Apophyllite forms square pyramidal or pseudo-cubic crystals, often colorless, white, or pale green, with a vitreous luster on crystal faces that turns pearly on its perfect basal cleavage. Hardness is about 4.5 to 5, streak is white, and a knife blade will scratch it. It is commonly confused with quartz or calcite, but its single perfect cleavage, lower hardness than quartz, and lack of a strong effervescent reaction to acid separate it from both.
Apophyllite identification checklist
| Color | Colorless, White, Green, Pink, Pale yellow | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous, pearly on cleavage | 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 basal, one direction | |
| Fracture | Uneven | |
| Specific gravity | 2.3–2.4 | Ordinary rock-like heft (specific gravity about 2.3499999999999996), similar to quartz. |
| Crystal system | Tetragonal |
Apophyllite look-alikes and how to tell them apart
Feldspar is harder (Mohs 6–6.5) than Apophyllite (Mohs 4.5–5), so Feldspar will scratch Apophyllite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Apophyllite vs Feldspar →
Apophyllite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Apophyllite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Apophyllite vs Calcite →
Both sit near Mohs 4.5–5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Apophyllite vs Analcime →
Both sit near Mohs 4.5–5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Apophyllite vs Apatite →
Apophyllite identification FAQ
How can you tell if a rock is Apophyllite?
Check the color (colorless, white, green, and pink), the vitreous, pearly on cleavage 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 Apophyllite?
Apophyllite 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 Apophyllite and Feldspar?
Apophyllite (Mohs 4.5–5, vitreous, pearly on cleavage luster) and Feldspar (Mohs 6–6.5, vitreous to pearly luster) look alike, but hardness, streak and heft usually separate them. See the full Apophyllite vs Feldspar comparison for a side-by-side table.
Is Apophyllite worth anything?
Entry-level Apophyllite 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 Apophyllite?
Apophyllite is most often colorless, white, green, and pink. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
