Comparison · Minerals
Actinolite vs Hornblende
Actinolite and Hornblende are easy to confuse because both are minerals. Both sit near Mohs 5–6, 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 Actinolite and Hornblende
- Both sit near Mohs 5–6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Actinolite leaves a white streak on unglazed porcelain, Hornblende leaves pale gray to colorless.
- They overlap in green and black, but Actinolite also comes in gray and Hornblende also comes in brown.
Actinolite vs Hornblende properties
| Property | Actinolite | Hornblende |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 5–6 | 5–6 |
| Luster | Vitreous to silky | Vitreous to silky |
| Streak | White | Pale gray to colorless |
| Transparency | Translucent to opaque | Translucent to opaque |
| Specific gravity | 3.0–3.2 | 3.0–3.4 |
| Crystal system | Monoclinic | Monoclinic |
| Common colors | Green, Dark green, Grayish green, Black | Black, Dark green, Dark brown |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Actinolite and Hornblende trade in a similar range, around $20.
About Actinolite
Actinolite is a calcium-magnesium-iron amphibole with the formula Ca2(Mg,Fe)5Si8O22(OH)2, part of the tremolite-actinolite-ferro-actinolite solid solution series. Its green color comes directly from iron substituting for magnesium within the crystal structure, and it typically grows as elongated, bladed to fibrous crystals. The mineral is best known to rockhounds as a key component of nephrite jade.
About Hornblende
Hornblende is the most common member of the amphibole mineral group, a complex calcium-iron-magnesium aluminosilicate that forms dark, elongated prismatic crystals in a wide variety of igneous and metamorphic rocks. It typically appears black to dark green and is easily recognized by a characteristic cleavage angle of about 56 and 124 degrees. Hornblende is a rock-forming mineral rather than a gem, though well-formed crystals are collected for their sharp form.
Actinolite vs Hornblende FAQ
Is Actinolite the same as Hornblende?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 5–6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Actinolite from Hornblende?
Both sit near Mohs 5–6, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Actinolite leaves a white streak on unglazed porcelain, Hornblende leaves pale gray to colorless. They overlap in green and black, but Actinolite also comes in gray and Hornblende also comes in brown.
Which is harder, Actinolite or Hornblende?
They are about equally hard, both near Mohs 5–6.
Which is more valuable, Actinolite or Hornblende?
Typical specimens of Actinolite and Hornblende trade in a similar range, around $20.
