Actinolite
A variety of Calcium Amphibole Subgroup
What is Actinolite?
Most often found in metamorphic rock, actinolite is a fibrous mineral that is a very rare type of asbestos. One variety of the material is nephrite, which is a form of jade. There is also a rare and highly sought catseye version of the mineral. Industrial asbestos is sometimes made from certain varieties of actinolite.
Etymology & Origins
The name actinolite is derived from the Greek word aktis (ἀκτίς), meaning "beam" or "ray", because of the mineral's fibrous nature.
Uses & Applications
In its fibrous form, actinolite has good insulating properties and was used as asbestos in the building industry until its carcinogenic and other debilitating health effects were discovered. Another form of this mineral is nephrite, better known as jade, which has abundant uses for jewelry and high-value carvings and works of art. Cat's eye actinolite is another gem-worthy form of the mineral. Transparent pieces are cut into faceted gemstones for jewelry.
Healing Properties
The connection between actinolite and the heart chakra supposedly protects the body, spirit, and mind from negative energies and emotional trauma. It's said to lessen felt stress and enhance immune response. If you need a confidence boost, actinolite is believed to do just that, increasing courage and self-assuredness in everyday life. Possession of actinolite may benefit the metabolic and adrenal systems.
Optical Properties
- Refractive Index
- 1.6-1.63
- Birefringence
- 0.03
- Pleochroism
- Distinct: yellow-green, light green, blue-green
- Optical Character
- Biaxial negative
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Associated Chakras
Key Characteristics
Formation of Actinolite
Actinolite is commonly found in metamorphic rocks, such as contact aureoles surrounding cooled intrusive igneous rocks. It also occurs as a product of metamorphism of magnesium-rich limestones. The old mineral name uralite is at times applied to an alteration product of primary pyroxene by a mixture composed largely of actinolite. The metamorphosed gabbro or diabase rock bodies, referred to as epidiorite, contain a considerable amount of this uralitic alteration. Fibrous actinolite is one of the six recognised types of asbestos, the fibres being so small that they can enter the lungs and damage the alveoli. Actinolite asbestos was once mined along Jones Creek at Gundagai, Australia.
Composition of Actinolite
Na2O, CaO, MgO, TiO2, MnO, Al2O3, FeO, Fe2O3, SiO2, H2O
Health & Safety Information
- ⚠️Harm Reason: Actinolite in powdered form can be toxic due to its Actinolite Asbestos content.
- ⚠️Physical Toxicity: Beware of asbestos. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer. And it can take years for symptoms related to the exposure to appear. Lapidaries should exercise caution when cutting this mineral.
- ⚠️How to prevent the risks of Actinolite?
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Quick Facts
Physical Properties
- Color
- Green, green-black, grey-green, black
- Hardness (Mohs)
- 5 - 6
- Density
- 3.07 g/cm³
- Streak
- White
- Luster
- Vitreous, Silky
- Crystal System
- Monoclinic
Chemical Properties
- Chemical Formula
- {Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
- Elements
- Ca, Fe, H, Mg, O, Si
Also Known As
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