Actinolite: beneficial properties of the stone and its magical meaning. Radiant stone actinolite References

Actinolite

The name of this mineral comes from the Greek words actinos- "ray" and lithos- "stone". You can guess that this name comes from the characteristic appearance of the stone - it seems to consist of many long needles. It is because of these needles that the stone has a delicate silky and sometimes glassy sheen.

Often thin inclusions of actinolite can be seen in quartz, rock crystal, beryl and other transparent gems. Gray-green quartz is the richest in actinolite crystals. There are several types of actinolite:

• actinolite-asbestos- the finest fiber variety, consisting of many parallel crystals and intergrowths. This is what we know under the name “asbestos” - this mineral is capable of breaking down into the finest elastic fibers, which are valuable fire-resistant raw materials.
• bissolite- is formed in the form of thin ordered crystals, differs from asbestos in structure and is not subject to splitting.
• nephritis- a very viscous and durable type of actinolite. It is distinguished by a wide palette of shades (from white to green of various saturations), is considered the most valuable mineral and is very popular in the jewelry industry.

Cabochon-treated actinolite can give a "cat's eye" effect (especially jade cabochons). Actinolite samples are a valuable acquisition for the collection: they are an interesting mineral that also has a pleasant appearance.

Geological certificate

Actinolite is a mineral from the amphibole group, one of the most common in the earth's crust. Its formula is Ca2(Mg, Fe2+)52(OH)2. An admixture of aluminum and sodium oxides is often found; the manganese-rich variety is called manganactinolite. Appearance - columnar, elongated needle-like or thread-like crystals. Color includes different shades of the green spectrum, from colorless to dark green. Hardness on the Mohs scale is 5.5-6.

Deposits: Russia (Transbaikalia) and some countries of the former USSR; Austria, USA (Alaska, Pennsylvania, Wyoming, Virginia, California), Canada, Brazil (Minas Gerais), Madagascar, etc.

Medicinal properties

It has been noticed that frequent wearing of actinolite or contact with it can relieve the owner of problems with skin or hair. If you feel itching, peeling or burning on your hands, lithotherapists recommend wearing actinolite bracelets on your wrists. If you want to get rid of dandruff and get thick hair, you should wear earrings or a pendant made of this mineral.

Magic properties

In the Urals, it has long been believed that whoever finds a crystal or fragment of actinolite attracts wealth and fame into his life, and can also soon expect the fulfillment of his cherished desire. This mineral helps to discern the truth and get rid of illusions. However, you should not accept it as a gift from the previous owner if you want to live your own life - there is a belief that this stone is able to “record” and correct the fate of its owner. So a brand new “unworn” stone is best suited as a talisman.

Chakra correspondence and Vastu Shastra

Actinolite is in good contact with the heart chakra (Anahata) and sacral chakra (Muladhara). Its energy is projective Yang. In the Vastu Shastra system of Vedic architecture, green actinolite can be replaced with emerald, corresponding to the planet Mercury (direction - North).

For zodiac signs

Actinolite is friendly to all zodiac signs. However, it has been noted that this mineral will help Scorpios find additional harmony and integrity.

Amulets and talismans

Actinolite stone is a symbol of fidelity, courage, and decency. As a talisman, it will help you better understand yourself and understand your interlocutor. It is also useful for students, students, and anyone who is engaged in any concentrated work, directing their attention.

— Actinolite translated from Greek “aktinos” and “lithos” means “radiant stone”. The composition consists of long and thin needle-shaped minerals, which consist of double chains of silicon atoms, such crystals form fibers that form radiant aggregates, which is why it is called radiant stone.

— There are other names for this stone - emerald spar, tremolite, stibolite, smaragdite, etc. Actinolite is often used as an ornamental stone.

— Fibrous inclusions of actinolite (hairs) create a “cat’s eye” effect and give many other transparent minerals their special beauty.

— The stone has a glassy sheen and a green color in a combination of shades of brown (brick, terracotta, chocolate, coffee) and green (herbal and tea, mint, jade and malachite, olive and pistachio, asparagus and emerald, marsh, etc.)

— Actinolite is mined in Russia (Lake Baikal), China, Taiwan, Africa, Canada, New Zealand and other countries.

Magic properties

— In China, they believe that actinolite “reads” the fate of the owner, influences him and even corrects the events destined for him. If the owner loses such a stone, no one on the street will pick it up, so that the fate of the former owner does not pass on to the finder.

— In ancient times in Rus' they believed that whoever found actinolite would soon become famous or get rich. African shamans believe that the magical properties of actinolite with the “cat’s eye” effect make it possible to detect lies. If the stone flickers in the hands, then the person is telling the truth, and if it dims and behaves differently when touched, then the person is lying.

- According to legend, it fulfills the owner’s deepest desire. This stone is monogamous, it cannot be given or given to others, it can belong to only one person, since he becomes one with the owner and, by leaving his stone, he can take his happiness and good luck with him.

— As a talisman, actinolite helps the owner better understand his feelings and desires, reveal deception and make the right decision. It is recommended to be worn by students, students and people engaged in scientific research; it will help its owner make the right decision and understand his aspirations.

— Jewelry with actinolite can be worn by people born under any zodiac sign, but it cannot be sold or given away.

Medicinal properties

— Actinolite promotes longevity, as well as emotional and physical stability of the body, and has a beneficial effect on a person’s overall well-being. Since ancient times, actinolite has been actively used in folk medicine to treat various diseases of the hair and skin.

- At , skin fungus and eczema, you need to wear the stone as jewelry on both hands; if the skin is peeling, the stone (be sure to set it in silver) should be worn on the middle finger of your right hand.

— Actinolite has a beneficial effect on the heart and sacral chakras, and accordingly prevents diseases associated with these chakras.

— All cardiovascular diseases and all lung diseases (including asthma) are associated with the heart chakra. It is responsible for normal blood circulation, respiratory organs and touch functions, lowers blood pressure, and stabilizes emotions.

— Diseases of the musculoskeletal system, perineum, spinal column, rectal diseases, blood circulation, metabolism, muscle strength, sex drive, and endurance are associated with the sacral chakra.

— If you have hair loss or dandruff, you need to wear earrings with a stone set in silver.

In nature, there is a very large group of silicates of complex composition, the main distinguishing feature of which is their tendency to form thin and long crystals. These compounds are called amphiboles (in Greek, “ambiguous”, “unclear”). Within the mineralogical group, actinolite can be considered the champion in terms of unclear properties, variability of composition and multiplicity of forms.

Green rays of actinolite

“Actis” in Greek means “ray”, therefore, actinolite means “radiant stone”. The beautiful name given to the mineral in 1794 by the Irishman Richard Kirwan does not reflect the fullness of the external properties of the stone. In most cases, actinolite is indeed similar to a petrified beam of rays - green rays at that - but that’s why amphiboles exist, to confuse connoisseurs...

Actinolite is not necessarily green, and not every sample of the mineral is opaque. In some places (Tanzania, India) actinolites are found of excellent quality and of a size sufficient for the manufacture of jewelry inserts.

And yet, the radiance of actinolite is its most important distinguishing feature! Interior decorations made of beautiful green stone with multiple clusters of veins in all possible variations play on the aesthetics of an outward-looking needle crystal. Particularly valued in gemology is jade.

Varieties of actinolite

The composition of actinolite, in addition to silicon oxide itself, includes oxidized calcium (usually “complete” with attached magnesium and iron) and a hydroxyl group. Magnesium, aluminum, titanium, and manganese may accompany silicon and calcium as impurities.

The crystal structure of such compounds (feldspar, wollastonite) is always columnar, but in actinolite, unlike its mineral “relatives,” the crystal needles are not compressed into even bundles, but diverge to the sides - like feathers in a fan or knitting needles in an umbrella.

The almost essential iron in actinolite gives the mineral its color. Different valent compounds of ferrous metal give crystals either a green or brown tint.

In addition to jade, actinolites include amianth (Greek for “pure”). In amianth, the fibers formed by translucent crystals are laid parallel and are easily separated from each other. This mineral is one of the amphibole asbestos. Its color range is located in the violet part of the spectrum.

Quartz with actinolite ingrowths is collectively called “hairy.” In Europe, from ancient times they were called “hair of Tethys” (the Latinized version of the name of the goddess Thetis). In the Eastern tradition, stones with “hairy” growths are called “Ali’s beard” (cousin of the Prophet Muhammad).

The best of the hairy ones exhibit a cat's eye effect. Fine-fiber varieties of actinolite found in the Alps are called byssolite - from the Greek “fine linen” (thin silk threads and fabric made from them).

Fine-grained actinolites with indistinguishable fibrousness are also found. Such stones are characterized by grass-green (preferably), green-brown, bluish-green, brown color and transparency. The best actinolites of this kind are called smaragdites and are highly valued, including on the jewelry market.

True, opaque actinolites with fibers twisted like felt are also called smaragdites. But terminological confusion is common in both mineralogy and gemology...

Actinolite properties: useful and not so useful

The mechanical and thermal strength of actinolite fibers is used in industry. The introduction of fibrous actinolite into rubber for car tires reduces the need for rubber. A mixture of polymer and mineral fiber increases the wear resistance of the tread, improves wheel-road traction, and allows the tires to be used under extreme load conditions.

As an ornamental stone, actinolite is close in expressiveness to malachite. Of particular interest to artists and architects are varieties of the mineral with atypical colors. In Italy (Piedmont), for example, actinolite is mined, the colors of which are predominantly blue.

Actinolite crystals of impeccable jewelry quality often end up in workshops, but rarely end up on retail shelves. The fragility of the material makes it difficult to process: it has never been possible to cut actinolite weighing more than twenty carats. It is even more difficult to wear jewelry with transparent actinolite: the stone should be protected from impacts and squeezing. Actinolite is insensitive to heat.

The name actinolite comes from the Greek “aktis” - ray and “litos” - stone. Aktinot, also known as actinolite. The English name of the mineral Actinolite is Actinolite

Actinolite radial-radiant aggregates. Ural

Synonyms: Actinolin - actynolin (Chester, 1896); actinote (Ayui, 1801); radiant stone-Strahlstein (Werner, 1789); pilite (Becke, 1883) - pseudomorph of fibrous actinolite after olivine; sillbolite - silbolite, sillbolite (Chester, 1896); glassy actinolite - bright green long-prismatic actinolite crystals (Dana, 1932); shtrahlite - strahlite (Chester, 1896); strelite - strelite (Chester, 1896); zillerthite (Delametri, 1797).

(Mg, Fe 2+ ) 5 (OH) 2

Chemical composition

The chemical composition of actinolite, taking into account isomorphic substitutions, is expressed by the formula: (Na, K) 0-0.5 (Ca 2-1.34 Na 0-0.66) [(Mg, Mn, Al, Ti) 4-2.5 ( Fe 2+ , Fe 3+ ) 1-2.5 ] [(Si 8-7.5 Al 0-o.5 ) (O, OH) 22 ] (OH, F, Cl, O) 2 .

Theoretical compositions:

Ca 2 Mg 4 FeSi 8 O 22 (OH) 2: CaO - 13.29; MgO - 9.11; FeO - 8.51; SiO 2 - 56.96; H 2 O - 2.13.

Ca 2 Mg 2.5 Fe 2.5 Si 8 O 22 (OH) 2: CaO - 12.59; MgO - 11.31; FeO - 20.15; SiO 2 - 53.93; H 2 O - 2.02.

CaO content from 9.3 to 13%; Unlike tremolites, Ca is often replaced by Na and group Y cations, especially in actinolites from glaucophane-containing rocks. Actinolites are known that are transitional to cummingtonites. MgO - usually from 12 to 20%, sometimes reduced to 9.5% (transition to ferroactinolites). Higher contents are possible with significant replacement of Ca by Mg. The total amount of Fe is conditionally limited to the range of 1-2.5 per formula unit, but actinolites with Fe>175 are rare. FeO from 7 to 19%, Fe 2 O 3 in the range of 0-5.5%. MnO from 0.15 to 0.55% (Mn0.02-0.07), rarely less or not detected; An increased MnO content was found in actinolite from the iron ore region of northeastern Labrador and in bissolite from an alpine-type vein at the Puiva deposit in the Urals. Manganese actinolite contains up to 7.4% MnO. Always contains small amounts of alkali metals. The Na 2 O content usually does not exceed 1%, but with a low calcium content it can reach 5.0%. The K 2 O content is no more than 0.65%, the highest in actinolites from aureoles of granitoid intrusions, the lowest in actinolites from glaucophane-containing rocks and ferruginous quartzites. The amount of Na + K is from 0.03 to 0.60, sometimes more, their amount in position A of the structure is up to 0.32. Al 2 O 3 - no more than 5%, absent in some actinolites. Cr 2 O 3 is rarely observed, as is P 2 O 5. SiO 2 content is within 51-56%. TiO 2 up to 0.3-0.8% (up to Ti 0.08); F-up to 0.3%, rare; Cl was detected only in actinolites from iron ore deposits.

Varieties

By composition:

Manganese actinolite - manganous actinolite. Discovered in skarns of the Kaso manganese deposit (Japan). Contains up to 7.38% MnO. Its properties are indistinguishable from ordinary actinolite. The most ferruginous manganese actinolite, dark green to gray-green, forms veins up to 5 cm thick, composed of irregular, partly elongated grains, contains inclusions of orthite, and is associated with lemon-yellow garnet. Less ferrous manganese actinolite in the form of colorless crystals was found as a product of hydrothermal alteration of skarn rhodonite; associated with brown garnet and manganphlogopite; some of its secretions are contained in hyalophane crystals.

Actinolite. Fiber aggregate

By the nature of the release:

Actinolite - asbestos- actinolite-asbeste - parallel-fibrous actinolite. It differs from tremolite-asbestos in its higher iron content. Synonyms like tremolite-asbestos. Actinolite-asbestos deposits are confined to zones of intense fracturing in altered basic volcanic rocks. Asbestos formation is associated with hydrothermal activity in areas of granite magmatism. Asbestos is contained in veins and veins that are not consistent along the strike, often irregular and with bulges. The length of the zones is up to hundreds of meters. Asbestos is cross- and longitudinally fibrous, the length of the fibers is up to 30 cm. Association with quartz, calcite, albite, epidote, axinite, and sometimes with ore minerals is typical. Small veins are usually monomineral. Examples of deposits: Grushinskoye (Yalta) in Northern Kazakhstan, Kyshgauzskoye in Central Kazakhstan, Gorbunovskoye in the Urals, Khatsavinskoye in the North Caucasus, Chazadyr in Tuva, Esenbulak in Mongolia. Actinolite-asbestos veinlets are also present in the hornfelsed sand-shale oligoclase-chlorite-epidote-actinolite rocks of Ak-Sika, Tuva Aut. region; in apogabbro chlorite-actinolite schists of the Tarcin region (Yugoslavia); in brecciated copper-nickel ore of the Allarechenskoye deposit on the Kola Peninsula. It is used, like tremolite-asbestos, for the manufacture of insulating and acid-resistant materials, but is inferior in quality. As the iron content increases, solubility increases, especially after heating at temperatures above 700°.

Actinolite-byssolite (Saussure, 1796) - tangled fibrous actinolite.
Synonym. Actinolitic zillerite (Fersman, 1913).
It differs from tremolite-bissolite in its increased iron content. Formed by hydrothermal alteration of basic rocks, gneisses, and crystalline schists; known in quartz veins; in the voids it envelops crystals of calcite, quartz, magnetite, titanite, albite, pennine, epidote, native silver, prehnite, pyrite, chalcopyrite; fibers are partially included in quartz and calcite crystals. Known in an Alpine-type vein in Puiva in the Subpolar Urals; in voids of desilified pegmatite and in veinlets among amphibolites in association with albite and scapolite in the Emerald Mines in the Urals; with epidote, calcite and grossular in the Kansai skarn lead-zinc deposit, Kuramin Mountains (Uzbekistan); in the voids of the garnet skarn in Mladenov (Bulgaria) it grows on epidote, quartz and calcite with siderite, limonite, desmin, chalcopyrite; in quartz veins cutting gabbroids in the Radautal valley, Harz (Germany); in the alpine veins of the Maderanertal valley (Switzerland); in Allermont (France); in South Oran (Algeria); in Buckingham (Canada).

Nephritis - dense cryptocrystalline masses composed of intertwining actinolite needles.

Uralite

Crystallographic characteristics

Syngony. Monoclinic.

Crystal structure

Isostructural with tremolite; Mg in octahedral positions is partially replaced by Fe 2+. Typically, the M(2) positions are depleted in Fe 2+ compared to M(1) and M(3). The distribution of iron between the M(1) and M(3) positions may be different.

Form of actinolite in nature

Crystals needle-shaped, prismatic.

Doubles according to (100) simple and polysynthetic. There are indications of twinning along (010) and (101).

Aggregates. Granular masses, porphyroblasts, columnar and radiant aggregates, parallel fibrous (asbestos) and tangled fibrous (bissolite) deposits.

Physical properties of actinolite

Optical

Color green, gray-green, bluish-green, almost colorless.

The streak is greenish-white.

The shine is strong glassy.

Tint to silky (for asbestos).

Transparency Transparent to translucent.

Mechanical

Hardness 5-6. Fragile.

Density 3.10-3.20.

Cleavage along (110) is perfect (at an angle of about 56°), less often along (010), sometimes separate along (100) and (101). The angles between the cleavage planes are 124 and 56 degrees, which determines the diamond-shaped or hexagonal shape of the crystals in cross section.

The fracture is splintered, stepped.

Chemical properties

Acids have almost no effect.

Other properties

Oxidation and dehydroxylation are also accompanied by a sharp increase in electrical conductivity; after dehydration is completed, it decreases again.

Artificial production of mineral

Actinolite synthesized under hydrothermal conditions at P H2O = 1000 bar and Pco 2 = 50 bar from a mixture of CaCO 3, MgC 2 O 4 -2H 2 O, FeC204-2H 2 O and SiO 2 gel. Complete isomorphic miscibility of tremolite and ferroactinolite has been established. The lower temperature limit of stability decreases from 500° for tremolite to 375° for a pseudoeutectic composition with 75% ferroactinolite. The mineral was also synthesized in the presence of Ca and Mg chlorides. Obtained in the system CaO-MgO-FeO-Al 2 O 3 -SiO 2 -H 2 O at 150-500° and 1-8 kbar.

Diagnostic signs

Diagnostics. Easily recognized by its needle-shaped crystals and radiant aggregates, green color, strong glass luster, perfect cleavage and fragility. It differs from pyroxenes in its cleavage angle of 124 and 56 degrees.

Associated minerals. Albite, epidote, chlorite, talc, glaucophane, crossite, sericite, garnet, quartz, calcite, stilpnomelane, pumpellyite, lawsonite, titanite, rutile, leucoxene, hematite, magnetite.

Origin and location

Metamorphic - in skarns (in contacts with limestones), found in crystalline schists (talc, chlorite). Sometimes it is the main rock-forming mineral (actinolite shales).

Actinolite is a rock-forming mineral of metamorphosed mafic rocks of the greenschist facies, found in hydrothermally altered igneous and metamorphic rocks, sometimes associated with the processes of formation of magnetite or copper-nickel ores.

At metamorphism of the main volcanogenic-sedimentary and subvolcanic rocks, actinolite forms in association with albite, epidote and chlorite, mainly along mafic minerals, but also replaces plagioclase. At the initial stages of metamorphism of volcanic-sedimentary rocks, detrital grains of hornblende are overgrown with actinolite, and fine-needle actinolite is released in the cement. In volcanogenic rocks, actinolite replaces phenocrysts of dark-colored minerals. During regressive metamorphism and in the process of metasomatism, actinolite is formed from dark-colored minerals of igneous and metamorphic rocks of basic, less often intermediate composition; in tectonically weakened areas it is deposited to form veins and nest-like accumulations, for example, in the Urals, on the Kola Peninsula, in Central Japan. Actinolite-asbestos veins are also found in fracture zones in the main rocks. During intense metamorphism, actinolite and albite-epidote-actinolite schists with chlorite, calcite, and sometimes muscovite are formed. However, actinolite hornblende is more common in shales than actinolite.
In greenschist strata, the albite-epidote-actinolite association is characteristic of zonal complexes and halos of granitoid intrusions. When moving to higher temperature associations of the amphibolite facies, zoned amphibole crystals appear with a core of relict actinolite and a shell of more intensely colored (often blue-green) hornblende. Zonal metamorphic complexes with actinolite as a rock-forming mineral are known in New Zealand, Scotland, and the Abukuma Plateau in Japan. In the Southern Urals, albite-epidote-actinolite rocks form a narrow cutting zone along the main volcanic rocks, pyroclasts and terrigenous-sedimentary rocks. The transition zone to unaltered rocks has a quartz-chlorite composition. The intensity of metamorphism and the amount of actinolite increase in dislocation zones, where a gradual transition to metasomatic rocks with pyrite mineralization is observed. Acicular and asbestos-like actinolite is found in pyrite deposits. Actinolite is found in halos of granitoid intrusions in California, the USA, South America, Tuva and other areas. In some places, the mineral is found in zones of contact between granitoids and volcanic-sedimentary or metamorphic rocks, for example, in the river basin. Tutkhun in Azerbaijan it is part of various hornfels of volcanic-sedimentary rocks; in the area of ​​the Emerald Mines in the Urals, it forms dense clusters and lens-shaped bodies up to 2.5 m long in the phlogopite zone of desilified pegmatites, composes reaction zones at the contact of diorite with serpentinites; in the area of ​​the Złoty Stock gold deposit in Lower Silesia (Poland), it is developed in amphibolites near the contact with granitoids. In an unusual paragenesis with biotite, K-feldspar, plagioclase and quartz, actinolite is found in the Durbachites of the Central Bohemian Massif, where it contains pyroxene relics and was probably formed during metamorphism.

In magnetite deposits associated with iron ore skarns and metasomatites, actinolite is a widespread mineral formed at various stages of the formation of these deposits. Actinolite, associated with albitization of host intrusive, carbonate and other rocks, is associated with albite, epidote, magnetite, titanite, apatite. It often replaces skarn minerals, while pyroxene-magnetite deposits are transformed into actinolite-magnetite deposits, while at the same time it is deposited in fracture zones with magnetite, quartz and carbonates. Actinolite of the most recent stages of mineral formation is associated with chalcopyrite, pyrrhotite, pyrite, and sphalerite. The iron content of actinolite is determined by the composition of the rocks it replaces and varies widely (low-iron actinolite in barren metasomatites and ferroactinolite in ore deposits). Examples of skarn-metasomatic iron ore deposits with widespread actinolitization are: Benkalinskoye, Shagyrkulskoye and Sorskoye in Southern Turgai, Lavrenovskoye in Kuznetsk Ala-Tau, Anzasskoye in Khakassia, Beloretskoye in Gorny Altai, the Irbinsky ore field and Odinochnoye deposits in the Eastern Sayan; deposits of the Norberg region in Sweden.
Actinolite is also known in ores and associated metasomatites of copper-nickel deposits; associated with biotite and ore minerals, in brecciated areas it composes asbestos veins or forms needle-shaped crystals deformed to helical shape. Examples: Allarechenskoye, Vostok and Pechenga deposits on the Kola Peninsula, nickel-bearing rocks of the Burma massif in the Far East. In Alpine-type veins, actinolite is released in the form of crystals and felt-like aggregates.

Actinolite is one of the common minerals in glaucophane-containing regionally metamorphosed breeds Associated with glaucophane, crossite, epidote, chlorite, sericite, albite, garnet, quartz, stilpnomelane, pumpellyite, lawsonite, titanite, rutile, leucoxene, hematite, magnetite. Often actinolite and glaucophane form different sections and zones of the same crystal, the boundaries between them are uneven but clear; in zoned crystals, actinolite usually composes the core, and glaucophane the outer zone, but reverse relationships are also possible; less often, both minerals form different grains. According to Klein, at low temperatures there is a miscibility gap in the actinolite-glaucophane series; at higher temperatures, a continuous transition from actinolite to glaucophane and crossite is possible. According to Brown, the association of actinolite with glaucophane is always disequilibrium and occurs in conditions bordering the glaucophane and greenschist facies; the overgrowth of one amphibole by another and partial replacement are caused by fluctuations in P - T conditions during the process of metamorphism. The Na content in the M(4) position of actinolite, which is in association with albite, chlorite and iron oxides, increases with increasing pressure; at certain temperatures it can be used for geobarometry. Actinolite in glaucophane and greenschists is known in the state. California and in Washington (USA), in Japan, in France, in Venezuela, on the island of Tasmania, in New Zealand.
In some ferruginous quartzites, actinolite is one of the most abundant silicates; associated with quartz, magnetite, hematite, chlorite, carbonates (calcite, dolomite or ankerite), cummingtonite, grunerite, sometimes with later alkaline amphiboles. Paragenesis varies somewhat depending on the composition of the original rocks and the degree of their metamorphism, for example, in hematite-magnetite quartzites KMA actinolite occurs with ankerite and dolomite, in magnetite quartzites it is more ferruginous and forms close intergrowths with calcite and magnetite; In some places the mineral is confined to calcareous layers. It is noted in ferruginous quartzites of the Kursk magnetic anomaly, Krivoy Rog basin, Olenegorsk and other deposits of the Kola Peninsula, in Canada in the province. Quebec and in the Itchen Lake region.

Mineral Change

During progressive metamorphism it is replaced by hornblende. In rocks of the glaucophane metamorphic facies and in ferruginous quartzites, actinolite was replaced by alkaline amphiboles, phlogopite or cummingtonite. Actinolite was replaced by epidote, zoisite, or an aggregate of zoisite and quartz; the (010) plane of actinolite is parallel to the (100) zoisite. Some actinolites are chloritized. The change in actinolite under hydrothermal conditions (T = 150-500°, P = 1-8 kbar) was studied experimentally.

Practical use

Fibrous varieties are used. Due to their high viscosity, jade and other tangled fibrous actinolite aggregates take polish well and serve as valuable ornamental stones.

Physical research methods

Differential thermal analysis

The DTA curve is similar to the curve for tremolite, but dehydration and decomposition of the actinolite structure, as well as melting of its decomposition products, occur at slightly lower temperatures; Along with pyroxene and cristobalite, iron oxides are present in the decomposition products. Additional endothermic effects on the DTA curves of actinolite may be due to impurities of calcite (750-800°), clinohumite (500-600°), and epidote (970-1000°). When actinolite is heated in an air atmosphere from approximately 400°, oxidation of divalent iron occurs.
The oxidation of iron is possibly accompanied by the separation of protons from hydroxyl groups. With intense oxidation, the weight loss upon heating is less than the water content in the mineral. Iron oxidation and partial dehydroxylation cause changes in the optical properties of actinolite. In the range of 400-600°, browning begins and a slow increase in refractive indices occurs, at 600-800° the color becomes red-brown, refractive indices increase sharply, especially in samples with a high Fe 2+ content (by 0.100 or more), the cNg angle decreases up to 10° (sometimes up to 2-5°), the 2V value drops slightly.

Ancient methods. It melts with difficulty under a blowpipe and produces grayish-green or greenish-black glass.

Crystal optical properties in thin preparations (sections)

In thin sections in transmitted light it is weakly colored, pleochroism by Ng is light green, grayish-green, rarely dark green, by Nm it is pale green or yellowish-green, by Np it is colorless or yellowish, sometimes pinkish. Brown tones of pleochroism are not typical. Sometimes there is uneven coloring of individuals. Biaxial (-), very rarely (+). The plane of the optical axes (010). In some actinolite asbestos, due to the deformation of the fibers, the extinction is direct. Elongation (+) n g = 1.640 - 1.665, n m = 1.625 - 1.650, n p = 1.615 - 1.643, n g - n p = 0.017 - 0.028. 2V = 70 - 84°, up to 87 and 90°18" with low Ca content. 2V = 40 - 50° was noted for asbestos varieties. Sometimes weak dispersion r< v. Двойникование. по (100) простое и полисинтетическое, указаны двойники по (010). Иногда под микроскопом обнаруживаются пластинчатые включения куммингтонита, ориентированные вдоль (100) и (101); частично они испытали собирательную перекристаллизацию. В актинолите из гор Руби (США) толщина пластинчатых включений куммингтонита до 50 мкм; их количество - 45% по объему. При неполном замещении актинолита обыкновенной роговой обманкой образуются сростки с общей осью b, границы между индивидами неровные, но четкие. В марганцевом актинолите отмечались включения ортита, окруженные плеохроичными двориками.

Photo gallery of the mineral

Actinolite (from the ancient Greek words ἀκτίς - ray and λίθος - stone) is a mineral of the amphibole group of the silicate class. It is an intermediate member between tremolite and ferro-actinolite. It has a needle-crystalline structure. Hardness 5.0 - 5.5. Transparent to opaque. The color is greenish - green-brown, green-gray, emerald green. Chemical formula Ca 2 (Mg,Fe) 5 2 (OH) 2. Fragile. Melts in the candle flame. Synonyms: radiant stone, cupzeferite, tafilite, zilbeloite, stibolite, etching.

Types of actinolite:
- Jade
- Amianth is asbestos.
- Bissolite – hairy aggregates consisting of the finest needle-shaped and microscopic fibrous crystals that easily break when bent.
- Smaragdite - continuous fine-grained masses of emerald-green actinolite.
- Emerald spar is an outdated name. Now the term has moved into the category of trade and can mean anything.

Asbestos and amianth actinolite cannot be wetted: it will stick together. Such specimens are of interest only to geologists and collectors. Some samples of asbestos actinolite look like a mane of fur. Very durable, by the way, you can even brush it with a brush, but it can easily be crushed by a touch or even a gust of wind. Samples of “shaggy” actinolite look sloppy in collections precisely because they do not hold their shape.

Unfortunately, the "hairies" are poisonous. Their small needles enter the respiratory tract and provoke silicosis, a severe and fatal disease. IT IS ABSOLUTELY IMPOSSIBLE to process fibrous actinolite at home. It is best to keep it in a closed display case to avoid it. This does not apply to other types of actinolite.

Inclusions of actinolite in other minerals create various optical effects: cat's eye in chrysoberyl and quartz, silky iridescence in spica quartz and tourmaline. Sometimes polished quartz with actinolite needles is found under the name hairworm, although it has nothing to do with real quartz hairworm - that is, golden needle-shaped rutile. Actinolite "hairy" has needle-like inclusions from emerald green to almost black. Some quartz are colored with tiny particles of actinolite; they are quite attractive in appearance, especially if the quartz itself is clean and transparent. Such samples are polished into cabochons and used as ornamental material for bracelets and beads and individual inserts. Transparent green quartz with a clean and even color - prasiolite - has nothing to do with actinolite quartz.

Green translucent actinolite is also used as an ornamental stone. It is also quite similar to jade, but differs in structure and is more fragile. It must be said that there are such ornamental jades, which are actually actinolites or a mixture of actinolite and jade, on the market. They are not sold under their own name and are similar in appearance, so it is not possible to really estimate the percentage of true jades from those masquerading as them. Small carvings and inserts are usually made from such pebbles. There are also rings made entirely of actinolite, which are very fragile and break quickly. Such handicrafts are not typical for branded sealed products.

Actinolite is characterized by a structure with parallel internal tubules. It may itself have a cat eye effect. Cat's eye jade is almost certainly actinolite, since the jade has all the fibers tangled inside.

Jewelry varieties of actinolite are rarely used due to the softness of the material - its hardness is close to the hardness of glass, and it breaks easily. Actinolite faceted with facets is a rare collectible stone.

Along with jade itself, actinolite is popular in China. There is even a [para]medical monograph from 1960 by the Chinese scientist Sue Tuoqiong, entirely devoted to the healing properties of actinolite.

The history of this mineral goes deep into the past, during the Stone Age. Until now, little remains of the previous ways of using actinolite (and it was not always just a decorative stone).

Actinolite was not known to Europe as an ornamental (and not only) stone - it was used as a source of asbestos. But in Africa it has been exploited since ancient times and is still used by local shamans. In particular, the "witch's finger" variety of actinolite from Zambia is a magical item.

Because of its specific “glory,” actinolite is often used as a material for occult objects, exotic jewelry, etc. Some varieties of actinolite are used in “black” lithotherapy, including in the specific African and New Zealand direction, Indian classical lithotherapy (for the support chakra ), not to mention Chinese. There are still healers living in Russia who know how to use the mineral for treatment.

Finding a collectible specimen of actinolite is easy, but finding a product made from it is much more difficult.