Comparison · Silicate Minerals
Leucite vs Orthoclase
Leucite and Orthoclase are easy to confuse because both are silicate minerals. Both sit near Mohs 5.75, 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 Leucite and Orthoclase
- Both sit near Mohs 5.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- They overlap in clear and yellow, but Leucite also comes in gray and Orthoclase also comes in pink.
- Well-formed crystals give it away: Leucite is tetragonal, Orthoclase is monoclinic.
Leucite vs Orthoclase properties
| Property | Leucite | Orthoclase |
|---|---|---|
| Type | Silicate Minerals | Silicate Minerals |
| Mohs hardness | 5.75 | 6 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | translucent | translucent |
| Specific gravity | 2.5 | 2.56 |
| Crystal system | tetragonal | monoclinic |
| Common colors | White, Gray, Colorless, Pale yellow | Colorless, White, Cream, Pink, Yellow |
| Rarity | uncommon | common |
| Typical specimen value | $5–$180+ | $5–$250+ |
Which is more valuable?
Typical specimens of Leucite and Orthoclase trade in a similar range, around $35.
About Leucite
Leucite is a potassium aluminum silicate feldspathoid that typically forms distinctive rounded, near-spherical trapezohedral crystals. It is white to gray and occurs as phenocrysts in potassium-rich volcanic rocks.
About Orthoclase
Orthoclase is a common potassium feldspar and a major rock-forming mineral in granitic rocks. It defines hardness 6 on the Mohs scale and appears as cream, pink, or colorless crystals and masses.
Leucite vs Orthoclase FAQ
Is Leucite the same as Orthoclase?
No. Both are silicate minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 5.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Leucite from Orthoclase?
Both sit near Mohs 5.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. They overlap in clear and yellow, but Leucite also comes in gray and Orthoclase also comes in pink. Well-formed crystals give it away: Leucite is tetragonal, Orthoclase is monoclinic.
Which is harder, Leucite or Orthoclase?
They are about equally hard, both near Mohs 5.75.
Which is more valuable, Leucite or Orthoclase?
Typical specimens of Leucite and Orthoclase trade in a similar range, around $35.
