Identification guide · Minerals
How to Identify Ametrine
Ametrine is identified by its side-by-side purple and yellow zones within a single transparent crystal, a pattern distinct from mixed amethyst-citrine assemblies glued together. It has vitreous luster, a hardness of 7, no cleavage, and the conchoidal fracture typical of quartz. The streak is white, though rarely tested on a transparent gem. Simulants include synthetic quartz grown with artificial color banding and dyed or irradiated glass, both of which lack quartz's hardness and natural inclusion patterns.
Ametrine identification checklist
| Color | Purple and yellow bicolor zoning | 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 Ametrine
Glass check. Ametrine 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.
Ametrine 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. Ametrine vs Quartz →
Ametrine is harder (Mohs 7) than Calcite (Mohs 3), so Ametrine will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Ametrine vs Calcite →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Ametrine vs Axinite →
Both sit near Mohs 7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Ametrine identification FAQ
How can you tell if a rock is Ametrine?
Check the color (purple and yellow bicolor zoning), 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 Ametrine?
Ametrine 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 Ametrine and Quartz?
Ametrine (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 Ametrine vs Quartz comparison for a side-by-side table.
Is Ametrine worth anything?
Entry-level Ametrine 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 Ametrine?
Ametrine is most often purple and yellow bicolor zoning. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
