RocksdayQuartz vs Topaz
How to tell them apart
The second most abundant mineral in Earth's crust. Clear crystals grow as six-sided prisms capped by a pointed termination, and quartz shows up as grains in sand, granite and countless other rocks.
Photo: Didier Descouens, CC BY-SA 4.0
A fluorine-bearing silicate and the Mohs reference for hardness 8. Crystals are often clear with sharp, diamond-shaped cross-sections.
Photo: Parent Géry, CC BY-SA 3.0
Quick tests
- Heft: Topaz feels noticeably heavier for its size (specific gravity 3.49–3.57 vs 2.65).
Key differences
- Topaz is harder, noticeably heavier in the hand and has one perfect cleavage.
- Quartz is softer, lighter and has no cleavage.
Side by side
| Property | Quartz | Topaz |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7 | 8 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Clear, White, Gray | Clear, Yellow, Orange, Blue, Pink |
| Crystal system | Trigonal | Orthorhombic |
| Specific gravity | 2.65 | 3.49–3.57 |
| Formula | SiO₂ | Al₂SiO₄(F,OH)₂ |
| Found in | Hot Springs, Arkansas; Minas Gerais, Brazil | Ouro Preto, Brazil; Topaz Mountain, Utah |
Properties that are the same for both are grayed out.
How to identify quartz
- Scratches glass easily and can't be scratched by a steel knife.
- Six-sided prisms with pointed ends when it forms crystals.
- Breaks with curved, shell-like (conchoidal) fractures — no flat cleavage planes.
- Does not fizz in vinegar or dilute acid.
Crystal system: Trigonal
Full Quartz guide →How to identify topaz
- Harder than quartz (8).
- One perfect cleavage across the crystal — flat, mirror-like breaks.
- Feels heavier than quartz of the same size.
- Prisms with lengthwise striations.
Crystal system: Orthorhombic
Full Topaz guide →More comparisons
Could you tell them apart from a blurry close-up?
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