Actinolite

Field of view: 10 mm. Plumosity crystals of grayish-green actinolite. The white basement is quartz. Actinolite is in the quartz vein traversing massive magnetite ore as shown below.

Recovered from a skarn deposit formed by contact metamorphism of I-type (Magnetite-series) quartz diorite. Formed in the late Miocene (6 Ma).

Actinolite from this location was described in 1949.

Field of view: 50 mm. Acicular actinolite in open spaces of magnetite-dominant ore. The black parts with a metallic luster are magnetite, and the grayish-green parts are aggregate of actinolite. Actinolite directly associated with magnetite is more greenish because of higher Fe content.