Comparison · Igneous Rocks vs Silicate Minerals
Anorthosite vs Microcline
Anorthosite and Microcline are easy to confuse. Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Anorthosite and Microcline
- Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Anorthosite leaves a white to pale gray streak on unglazed porcelain, Microcline leaves white.
- Luster is different: Anorthosite is pearly while Microcline is vitreous.
- Hold a thin edge to the light: Anorthosite is opaque, Microcline is translucent.
- They overlap in white, gray, and pink, but Anorthosite also comes in blue and black and Microcline also comes in green.
Anorthosite vs Microcline properties
| Property | Anorthosite | Microcline |
|---|---|---|
| Type | Igneous Rocks | Silicate Minerals |
| Mohs hardness | 6 | 6 |
| Luster | pearly | vitreous |
| Streak | White to pale gray | White |
| Transparency | opaque | translucent |
| Specific gravity | 2.75 | 2.56 |
| Crystal system | varies | triclinic |
| Common colors | White, Gray, Blue gray, Black, Pale pink | White, Cream, Pink, Green, Gray |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $5–$300+ |
Which is more valuable?
Microcline is usually the more valuable of the two: a typical collector specimen runs about $40 against $10 for Anorthosite, and premium Microcline can reach $300 or more.
About Anorthosite
Anorthosite is a coarse-grained igneous rock made mostly of plagioclase feldspar. It often looks light gray to white, sometimes with dark mafic minerals or bluish feldspar flashes.
About Microcline
Microcline is a potassium-rich feldspar and a rock-forming mineral in granites and pegmatites. Its blue-green gem variety, amazonite, is widely collected, while ordinary microcline appears as cream, pink, or gray crystals and masses.
Anorthosite vs Microcline FAQ
Is Anorthosite the same as Microcline?
No. Anorthosite is a igneous rock while Microcline is a silicate mineral. Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Anorthosite from Microcline?
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Anorthosite leaves a white to pale gray streak on unglazed porcelain, Microcline leaves white. Luster is different: Anorthosite is pearly while Microcline is vitreous.
Which is harder, Anorthosite or Microcline?
They are about equally hard, both near Mohs 6.
Which is more valuable, Anorthosite or Microcline?
Microcline is usually the more valuable of the two: a typical collector specimen runs about $40 against $10 for Anorthosite, and premium Microcline can reach $300 or more.
