Identification guide · Quartz Family
How to Identify Amethyst
Amethyst is usually purple, violet, and deep purple 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 Clear Quartz, Citrine, and Quartz; the tests below separate them.
Amethyst identification checklist
| Color | Purple, Violet, Deep Purple, Lavender | 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 | Hexagonal |
Extra tests for Amethyst
Glass check. Amethyst 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.
Amethyst 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. Amethyst vs Clear Quartz →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Amethyst vs Citrine →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Amethyst vs Quartz →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Is my Amethyst real?
- Hardness: real Amethyst sits at Mohs 7. Glass imitations are about 5.5, so genuine Amethyst 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
- Check whether the specimen's color and texture match typical Amethyst examples.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Amethyst identification FAQ
How can you tell if a rock is Amethyst?
Check the color (purple, violet, deep purple, and lavender), 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 Amethyst?
Amethyst 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 Amethyst and Clear Quartz?
Amethyst (Mohs 7, vitreous luster) and Clear Quartz (Mohs 7, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Amethyst vs Clear Quartz comparison for a side-by-side table.
How do I know if my Amethyst is real?
Real Amethyst 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 Amethyst worth anything?
Entry-level Amethyst specimens sell for around $10, typical collector pieces about $50, and premium examples $500 or more depending on size, quality and locality.
What color is Amethyst?
Amethyst is most often purple, violet, deep purple, and lavender. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
