Guide
Actinolite specimens for sale
28 for sale · $3–$7,500 USD
87 in the gallery
Actinolite is a monoclinic amphibole mineral that forms in elongated, slender crystals and fibrous masses. It commonly exhibits a green color range from pale to dark, with a vitreous to silky lustre and a characteristic bladed or needle-like habit in some specimens. The mineral often occurs in contact metamorphic rocks and hydrothermal environments, where it can form as part of actinolite-tass taught assemblages within hornfels and greenschist facies rocks.
- Formula
- Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
- Rarity
- Common
- Stability
- Stable
- Collector interest
- Moderate Interest
- Classification notes
- Inosilicate, Amphibole group; member of the actinolite-tremolite series
Key characteristics
- Crystal system
- monoclinic
- Mohs hardness
- 5–6
- Specific gravity
- 3–3.3
- Luster
- vitreous, silky
- Transparency
- transparent, translucent, opaque
- Color
- green, gray, black
- Streak
- white
- Cleavage
- good
- Fracture
- uneven, splintery
- Crystal habit
- prismatic, acicular, fibrous, radiating, granular, massive
- Gem mineral
- Classic / historic
Buy Actinolite specimens
View all 28Where Actinolite is found
Top localities
- Knappenwand6 specimens
- Tormiq Valley4 specimens
- Pakistan2 specimens
- Capelinha2 specimens
- Kongwa2 specimens
- Tilly Foster Iron Mine2 specimens
- Upper Kohistan District2 specimens
- Afghanistan1 specimen
- Indonesia1 specimen
- Switzerland1 specimen
Guides
All guidesAbout Actinolite
Notable specimens come from producing localities in Pakistan, Tanzania, Austria, the United States, and Namibia. Collectors value actinolite for its color variety and the texture of stony to fibrous aggregates, which can create striking visual contrasts when cut or sliced for display. Larger, well-formed crystals and concentrated fibrous masses are particularly sought after for their mineralogical interest and aesthetic appeal.
