Comparison · Igneous Rocks
Basaltic Andesite vs Tephrite
Basaltic Andesite and Tephrite are easy to confuse because both are igneous rocks. 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 Basaltic Andesite and Tephrite
- Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- They overlap in gray, black, and brown, but Basaltic Andesite also comes in red and Tephrite also comes in green.
Basaltic Andesite vs Tephrite properties
| Property | Basaltic Andesite | Tephrite |
|---|---|---|
| Type | Igneous Rocks | Igneous Rocks |
| Mohs hardness | 6 | 6 |
| Luster | dull | dull |
| Streak | Gray to dark gray | Gray to dark gray |
| Transparency | opaque | opaque |
| Specific gravity | 2.85 | 2.85 |
| Crystal system | varies | varies |
| Common colors | Dark gray, Black, Brown, Red brown, Gray | Dark gray, Black, Brown, Gray, Greenish black |
| Rarity | common | uncommon |
| Typical specimen value | $1–$75+ | $1–$75+ |
Which is more valuable?
Typical specimens of Basaltic Andesite and Tephrite trade in a similar range, around $10.
About Basaltic Andesite
Basaltic andesite is a dark volcanic rock between basalt and andesite in composition. It can look fine-grained, dark gray to black, and may contain small crystals or vesicles.
About Tephrite
Tephrite is a dark, fine-grained volcanic rock that contains feldspathoid minerals such as nepheline or leucite. It can resemble basalt in hand sample.
Basaltic Andesite vs Tephrite FAQ
Is Basaltic Andesite the same as Tephrite?
No. Both are igneous rocks, but they are distinct rock types with different hardness, streak or luster. 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 Basaltic Andesite from Tephrite?
Both sit near Mohs 6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. They overlap in gray, black, and brown, but Basaltic Andesite also comes in red and Tephrite also comes in green.
Which is harder, Basaltic Andesite or Tephrite?
They are about equally hard, both near Mohs 6.
Which is more valuable, Basaltic Andesite or Tephrite?
Typical specimens of Basaltic Andesite and Tephrite trade in a similar range, around $10.
