Comparison · Feldspar Group vs Semi-Precious Stones
Feldspar vs Moonstone
Feldspar and Moonstone are easy to confuse. Both sit near Mohs 6–6.5, 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 Feldspar and Moonstone
- Both sit near Mohs 6–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Feldspar is Transparent to translucent, Moonstone is translucent.
- They overlap in pink and gray, but Feldspar also comes in green and clear and Moonstone also comes in white and blue.
- Well-formed crystals give it away: Feldspar is Monoclinic to Triclinic (depending on species), Moonstone is monoclinic.
Feldspar vs Moonstone properties
| Property | Feldspar | Moonstone |
|---|---|---|
| Type | Feldspar Group | Semi-Precious Stones |
| Mohs hardness | 6–6.5 | 6 |
| Luster | Vitreous to pearly | vitreous |
| Streak | White | White |
| Transparency | Transparent to translucent | translucent |
| Specific gravity | 2.55–2.76 | 2.6 |
| Crystal system | Monoclinic to Triclinic (depending on species) | monoclinic |
| Common colors | White, Pink, Gray, Green (amazonite), Colorless | White, Gray, Peach, Blue sheen |
| Rarity | common | uncommon |
| Typical specimen value | $2–$150+ | $10–$500+ |
Which is more valuable?
Moonstone is usually the more valuable of the two: a typical collector specimen runs about $50 against $20 for Feldspar, and premium Moonstone can reach $500 or more.
About Feldspar
Feldspar is not a single mineral but a group of related aluminosilicate minerals, comprising the potassium feldspars, orthoclase, microcline, and sanidine, and the plagioclase series running from albite to anorthite, together making up roughly 60 percent of Earth's crust by volume. All share a similar framework silicate structure, two cleavage directions near 90 degrees, and moderate hardness, but differ in composition, color, and crystal system. As the most abundant mineral group on the planet, feldspar defines granite, basalt, gneiss, and countless other rock types.
About Moonstone
Moonstone is a feldspar mineral known for its adularescence—a billowy blue-white light that moves across the surface like moonlight on water.
Feldspar vs Moonstone FAQ
Is Feldspar the same as Moonstone?
No. Feldspar is a feldspar group while Moonstone is a semi-precious stone. Both sit near Mohs 6–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Feldspar from Moonstone?
Both sit near Mohs 6–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Feldspar is Transparent to translucent, Moonstone is translucent. They overlap in pink and gray, but Feldspar also comes in green and clear and Moonstone also comes in white and blue.
Which is harder, Feldspar or Moonstone?
They are about equally hard, both near Mohs 6–6.5.
Which is more valuable, Feldspar or Moonstone?
Moonstone is usually the more valuable of the two: a typical collector specimen runs about $50 against $20 for Feldspar, and premium Moonstone can reach $500 or more.
