Contrary to the provided subject description, actinolite is not a city in Canada. It is an amphibole silicate mineral characterized by the chemical formula Ca2(Mg4.5–2.5Fe2+0.5–2.5)Si8O22(OH)2.
As a mineral species, actinolite is defined by its specific chemical composition and crystalline structure. It belongs to the amphibole group of silicate minerals.