Actinolite is a mineral that belongs to the amphibole group of silicates. It is commonly found in metamorphic rocks, such as contact aureoles surrounding cooled intrusive igneous rocks. Actinolite is also found as a product of metamorphism of magnesium-rich limestones.

Actinolite is a powerful heart stone that provides one’s emotional body with protection from negative energies. It is often associated with the precious stone emerald for its similar lush green hues. In fact, high-quality, emerald-green actinolite masses are sometimes called “emerald spar”. As such, actinolite can be an affordable alternative to emerald as a May birthstone.

Actinolite is also used as a gemstone. One form of actinolite is nephrite, one of the two types of jade (the other being jadeite, a variety of pyroxene). Another gem variety is the chatoyant form known as cat’s-eye actinolite. This stone is translucent to opaque and green to yellowish-green in color.