Identification guide · Silicate Minerals
How to Identify Prasiolite
Prasiolite is usually green, pale green, and yellowish green with a vitreous luster and is transparent. It has a Mohs hardness of 7. It scratches glass and a steel knife and cannot be scratched by a steel file. Its streak is white. It is most often confused with Quartz, Clear Quartz, and Calcite; the tests below separate them.
Prasiolite identification checklist
| Color | Green, Pale green, Yellowish 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 | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 7 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.65 | Ordinary rock-like heft (specific gravity about 2.65), similar to quartz. |
| Crystal system | Trigonal |
Extra tests for Prasiolite
Glass check. Prasiolite 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.
Prasiolite look-alikes and how to tell them apart
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Prasiolite vs Quartz →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Prasiolite vs Clear Quartz →
Prasiolite is harder (Mohs 7) than Calcite (Mohs 3), so Prasiolite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Prasiolite vs Calcite →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Is my Prasiolite real?
- Hardness: real Prasiolite sits at Mohs 7. Glass imitations are about 5.5, so genuine Prasiolite scratches glass while a glass fake cannot.
- Bubbles: round gas bubbles under a 10x loupe mean glass or resin, never a natural stone.
- Color: dyed material concentrates color in cracks and pores; look for pigment collecting at the edges of fractures.
- Temperature: natural crystals feel cool and take longer to warm in your hand than plastic or resin.
Field tips
- Look for a pale, slightly yellowish leek-green color in transparent quartz with glassy luster.
- Prasiolite has quartz hardness near 7, no cleavage, and a conchoidal fracture.
- Most green quartz is heat-treated; natural prasiolite is uncommon and best confirmed by a gemologist.
Prasiolite identification FAQ
How can you tell if a rock is Prasiolite?
Check the color (green, pale green, and yellowish green), the vitreous luster, a Mohs hardness of 7 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Prasiolite?
Prasiolite has a Mohs hardness of 7. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Prasiolite and Quartz?
Prasiolite (Mohs 7, vitreous luster) and Quartz (Mohs 7, vitreous, greasy on fracture surfaces luster) look alike, but hardness, streak and heft usually separate them. See the full Prasiolite vs Quartz comparison for a side-by-side table.
How do I know if my Prasiolite is real?
Real Prasiolite matches the hardness listed above, shows no round gas bubbles under magnification, and does not concentrate dye in cracks. Glass and resin fakes fail at least one of those checks.
Is Prasiolite worth anything?
Entry-level Prasiolite specimens sell for around $10, typical collector pieces about $60, and premium examples $300 or more depending on size, quality and locality.
What color is Prasiolite?
Prasiolite is most often green, pale green, and yellowish green. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
