RocksdayAmethyst vs Spodumene
How to tell them apart
The purple variety of quartz. Its color comes from traces of iron combined with natural radiation, and it often lines the inside of large volcanic geodes.
Photo: Gonzalo Devia, CC BY-SA 4.0
A lithium silicate from granite pegmatites. Pink kunzite and green hiddenite are its gem forms; plain spodumene is a major lithium ore.
Photo: Parent Géry, CC BY-SA 3.0
Key differences
- Amethyst is harder and has no cleavage.
Side by side
| Property | Amethyst | Spodumene |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7 | 6.5–7 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Purple | Pink, Purple, Green, White |
| Crystal system | Trigonal | Monoclinic |
| Specific gravity | 2.65 | 3.1–3.2 |
| Formula | SiO₂ | LiAlSi₂O₆ |
| Found in | Rio Grande do Sul, Brazil; Artigas, Uruguay | Greenbushes, Western Australia; Afghanistan |
Properties that are the same for both are grayed out.
How to identify amethyst
- Purple, often deepest at the crystal tips.
- Hardness 7 — scratches glass.
- Grows as clusters of pointed crystals inside geodes.
- No cleavage; breaks with a glassy, curved fracture.
Crystal system: Trigonal
Full Amethyst guide →How to identify spodumene
- Flattened, striated prisms, often lilac-pink.
- Two cleavages at nearly 90° — splits easily.
- Color looks deepest down the length of the crystal.
Crystal system: Monoclinic
Full Spodumene guide →More comparisons
Could you tell them apart from a blurry close-up?
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