Ferro-actinolite is the ferrous iron rich endmember of the actinolite - tremolite continuous solid solution series of the double chain calcic amphibole group of inosilicate minerals. All the series members belong to the monoclinic crystal system.

Ferro-actinolite is the ferrous iron rich endmember of the actinolite - tremolite continuous solid solution series of the double chain calcic amphibole group of inosilicate minerals. All the series members belong to the monoclinic crystal system.