It belongs to a series with the minerals tremolite and ferro-actinolite . A series occurs when ions can freely substitute between each other. In this case, when iron is predominant the mineral is ferro-actinolite and when magnesium is predominant the mineral is tremolite. Actinolite is the intermediate member. Other minerals also form asbestos such as serpentine and the minerals of the series mentioned above.
Serpentine asbestos is more widely used and of a better grade in general.
Although asbestos has been shown to cause cancer in humans when inhaled in high enough concentrations, it still has many valuable applications. Asbestos is used for fire retardant materials and brake shoes and pads. Its prior use as insulation has been all but eliminated due to health concerns. A variety of actinolite, nephrite , is one of the two minerals called jade . The other jade mineral is jadeite .