Actinolite is an amphibole that is generally dark in color. Actinolite (pronounced ak-TIN-uh-lyte) can appear in
multiple forms such as dense and compact or brittle and fibrous, along with different colors, including white, gray,
brown or green. The mineral’s name stems from the Greek “aktinos,” meaning “ray” or “beam,” stemming from its
radiating fibrous form.
Actinolite is made up of other minerals and substances such as Calcium, Magnesium, Iron, Silicon, Oxygen and
Hydrogen. Actinolite is typically used with the similar mineral vermiculite, which expands when heated. Vermiculite
and actinolite make for an effective, light-weight insulation material. Other common uses for actinolite and
vermiculite include Insulation material, Gardening, Concrete materials used in construction and Structural fire-
proofing. Actinolite may still be present in buildings, homes or other locations that were constructed before
asbestos was known to be a hazardous material. This material has been found in products such as Paints,
Sealants, Drywall, Joint compounds and Children's toys
Amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. Amphiboles are minerals of either
igneous or metamorphic origin; in the former case occurring as constituents (hornblende) of igneous rocks, such
as granite, diorite, andesite and others. Those of metamorphic origin include examples such as those developed
in limestones by contact metamorphism (tremolite) and those formed by the alteration of other ferromagnesian
minerals (hornblende). Pseudomorphs of amphibole after pyroxene are known as uralite.
The name amphibole (from the Greek word amphibolos meaning 'ambiguous') was used by René Just Haüy to
include tremolite, actinolite, tourmaline and hornblende. The group was so named by Haüy in allusion to the
protean variety, in composition and appearance, assumed by its minerals. This term has since been applied to
the whole group.
Four of the amphibole minerals are among the minerals commonly called asbestos. These are: Anthophyllite,
Riebeckite, Cummingtonite/Grunerite series, and Actinolite/Tremolite series. The Cummingtonite/Grunerite series
is often termed Amosite,or Brown Asbestos and Riebeckite is known as Crocidolite or Blue Asbestos. These are
generally called Amphibole Asbestos.
Anthophyllite, Holmquistite and Ferrogedrite
Tremolite, Actinolite, Cummingtonite, Grunerite, Hornblende, Glaucophane, Riebeckite (or Crocidolite),
Arfvedsonite, Richterite, Pargasite, Winchite and Edenite.
Due to the wide variations in chemical composition, the different members vary considerably in properties and
general appearance. Anthophyllite occurs as brownish, fibrous or lamellar masses with hornblende in mica-schist
at Kongsberg in Norway and some other localities. An aluminous related species is known as gedrite and a deep
green Russian variety containing little iron as kupfferite. Hornblende is an important constituent of many igneous
rocks. It is also an important constituent of amphibolites formed by metamorphism of basalt.
Actinolite is an important and common member of the monoclinic series, forming radiating groups or acicular
crystals of a bright green or greyish-green color. It occurs frequently as a constituent of green schists. The name
(from Greek a 'ray' and a 'stone') is a translation of the old German word Strahlstein (radiated stone).
Glaucophane, crocidolite, riebeckite and arfvedsonite form a somewhat special group of alkali-amphiboles. The
first two are blue fibrous minerals, with glaucophane occurring in blueschists and crocidolite (blue asbestos) in
ironstone formations, both resulting from dynamo-metamorphic processes. The latter two are dark green
minerals, which occur as original constituents of igneous rocks rich in sodium, such as nepheline-syenite and
information paraphrased and photos courtesy of;
|One of our customers wanted us to locate some Actinolite in Talc from North Carolina. We were able to locate
a few specimens but we had to research Actinolite and thought we would pass that information on to our
customers. We found out that Actinolite is a type of Asbestos. We discovered this form is not very dangerous.
The fine acicular type is the most dangerous. Please handle these specimens rarely, and always wear gloves
or/and wash your hands after handling the specimens. Do not saw, sand or polish these specimens as the dust
may get into your lungs.
|Item # ACTIN07169051
Actinolite in Talc
|This piece is the last of the specimens of Actinolite in Talc that were obtained
from a Mineral dealer in Franklin, NC. This piece is from the Carolina Talc
Mine (Kinsey Mine, Bailey Mine, Notla Mine) in the Murphy Marble Belt region
in Cherokee County, North Carolina.
This specimen weighs 6.9 oz or 0.43 lb (197g) and measures
3.4 x 2.2 x 1.2 inches (8.8 x 5.7 x 3.1 cm)