Identification guide · Minerals
How to Identify Analcime
Analcime forms colorless, white, or pale pink trapezohedra with rounded, many-faced outlines, sometimes resembling small soccer balls. Luster is vitreous to slightly greasy, streak is white, and hardness runs 5 to 5.5. It lacks cleavage and breaks with a conchoidal fracture. Because it shares vesicle-filling habits with other zeolites, crystal shape is the most reliable clue; leucite looks similar but occurs in potassium-rich lavas rather than basalt cavities.
Analcime identification checklist
| Color | Colorless, White, Gray, Pink, Pale green | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | 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 | 5–5.5 | 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 | Poor, indistinct cubic | |
| Fracture | Conchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.24–2.29 | Noticeably light in the hand for its size (specific gravity about 2.265). |
| Crystal system | Isometric |
Extra tests for Analcime
Glass check. Analcime 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.
Analcime look-alikes and how to tell them apart
Feldspar is harder (Mohs 6–6.5) than Analcime (Mohs 5–5.5), so Feldspar will scratch Analcime and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Analcime vs Feldspar →
Analcime is harder (Mohs 5–5.5) than Calcite (Mohs 3), so Analcime will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Analcime vs Calcite →
Albite is harder (Mohs 6–6.5) than Analcime (Mohs 5–5.5), so Albite will scratch Analcime and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Analcime vs Albite →
Both sit near Mohs 5–5.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Analcime vs Apophyllite →
Analcime identification FAQ
How can you tell if a rock is Analcime?
Check the color (colorless, white, gray, and pink), the vitreous luster, a Mohs hardness of 5–5.5 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Analcime?
Analcime has a Mohs hardness of 5–5.5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Analcime and Feldspar?
Analcime (Mohs 5–5.5, vitreous luster) and Feldspar (Mohs 6–6.5, vitreous to pearly luster) look alike, but hardness, streak and heft usually separate them. See the full Analcime vs Feldspar comparison for a side-by-side table.
Is Analcime worth anything?
Entry-level Analcime 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 Analcime?
Analcime is most often colorless, white, gray, and pink. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
