tremoliaktinoliittiryhmä

Tremoliaktinoliittiryhmä refers to a group of amphibole minerals characterized by their chemical composition and crystal structure. This group includes tremolite and actinolite, which are solid solution end-members. Tremolite has a general formula of Ca2Mg5Si8O22(OH)2, while actinolite is Ca2Fe5Si8O22(OH)2. Intermediate compositions between these two are also common and are often referred to as ferroactinolite or tremolite-actinolite solid solution.

These minerals typically form in metamorphic rocks, such as marbles, schists, and amphibolites. They are also found in some igneous rocks. The color of tremoliaktinoliittiryhmä minerals can range from white or colorless (tremolite) to green or black (actinolite), depending on the iron content. Their hardness is typically between 5 and 6 on the Mohs scale, and they often exhibit a prismatic or fibrous habit.

The presence of tremoliaktinoliittiryhmä minerals can indicate specific metamorphic conditions, such as moderate to high temperatures and pressures. They are important rock-forming minerals in many geological settings. In some cases, fibrous varieties of actinolite can be associated with asbestos minerals, though tremolite itself is generally considered less hazardous. Geologists study these minerals to understand the metamorphic history and petrogenesis of rocks.