The mineral orthoclase belongs to the group of alkali feldspars. It got its name from the mineralogist Breithaupt in 1823. Translated from Greek, "orthos" - straight, "klasus" - refraction. Indeed, a feature of orthoclase is the angle of 90° between the cleavage planes. The mined stone has an opaque color with a pink, green, red, brown, yellow, white or gray tint, unevenly distributed throughout the volume.
Origin
Orthoclase has a magmatic, postmagmatic and partially metamorphic origin. Its formation occurred as a result of the solidification of natural melts - lava, magma, and also as a result of transformations of rocks due to physical and chemical changes in the environment.
Deposits
In Russia, the orthoclase mineral is mined in the following regions:
- Udorskydistrict of the Republic of Komi.
- Lovozersky district of the Murmansk region.
- Pitkyarantsky district of Karelia.
- Zelenchuksky district in Karachay-Cherkessia.
- Kaslinsky, Verkhneuralsky districts of the Chelyabinsk region.
- Asbestovsky and Gornouralsky urban districts of the Sverdlovsk region.
- Rubtsovsky district of the Altai Territory.
- Olkhonsky and Slyudyansky districts of the Irkutsk region.
- Verkhoyansk and Aldan regions in Yakutia.
- Ayano-Maisky and Tuguro-Chumikansky districts of the Khabarovsk Territory.
- Milkovsky district of the Kamchatka Territory.
From the countries of the former USSR, production is carried out in Kazakhstan, Kyrgyzstan, Tajikistan, Ukraine. Deposits of valuable varieties of the orthoclase mineral can boast of Sri Lanka, Burma, India, Brazil, Australia, Italy. One of the rarest species - transparent orthoclase - is found only in Madagascar. Large deposits are located in the Czech Republic, Kyrgyzstan, Austria, Germany, Mexico.
Composition
The chemical formula of the mineral orthoclase is KAlSi3O8 – potassium aluminosilicate. It consists of:
- 64, 4% silicon dioxide (SiO2).
- 18% aluminum oxide (Al2O3).
- 16, 6% potassium oxide (K2O).
- 1% impurities of sodium oxide (Na2O), barium (Ba), rubidium (Rb), sodium (Na).
Properties
Orthoclase mineral has a glassy or pearly luster, brittle in structure, has a density of 2.56 g/cm3. Able to dissolve in nitric acid and has electrical insulating properties. Outwardly, it has a continuous dense structure with inclusions and uneven stepped fractures. Orthoclase mineral class according to IMA and USSR taxonomy - silicates.
Some properties of the stone are shown in the table below.
| Property | Meaning |
| Transparency |
Transparent, translucent, opaque |
| Crystal shape | Columnar, tabular, prismatic |
| Mohs hardness | 6 |
| Singony | Monoclinic |
| Refraction | 1, 520-1, 525 |
| Birefringence | 0, 005 |
| Cleavage | Clear, perfect |
| Molecular weight | 278, 33 |
| Pleochroism | Not pleochroic |
| Optical Relief | Low |
Types of mineral
Physical properties and color make it possible to distinguish several types of orthoclase mineral:
- Sunstone is a transparent mineral of gold or yellow hue. After cutting, it acquires a delightful brilliance, which is why it is popular in jewelry. Some of the stones of thisspecies can weigh over 100 carats.
- Moonstone has a bluish-silver hue. This is the purest stone in composition, has a bewitching cold radiance, which is achieved due to its structure.
- Adularia (also called ice spar) is a dull, colorless, transparent mineral, which is wedge-shaped crystals. Due to its unattractive appearance, it is not used in jewelry, but is a frequent participant in various exhibitions and collections.
- Sanidin is a glassy stone interspersed with tabular crystals shining in the light. Has a warm tan hue.
- Microline is a light milky mineral with transparent edges.
Some jewelers use the classification of orthoclase minerals by shades:
- wolf eye - pearl gray tones;
- lennilite - green shades;
- water orthoclase - colorless minerals;
- ferriortoclase - yellow shades;
- erythritol - the predominance of red tones.
Application
Due to its characteristics, orthoclase mineral has found wide application in the following areas:
- ceramic industry (production of porcelain, enamels, faience, glaze);
- glass industry;
- production of paints and varnishes;
- construction: production of tiles, finishing materials;
- electrical engineering;
- jewelry industry.
Orthoclase has no great value, therefore it is more often used as beads, cabochons, imitation of other natural stones. Some specimens of sun and moon stones, due to their beautiful appearance and radiance, can be used in decorative jewelry.
Transparent orthoclase stones are of particular value to collectors as they are rarely found in nature. In addition, they require careful handling due to their high fragility.
Healing properties
Traditional medicine uses the mineral orthoclase to treat depressive conditions in people, as well as when working with the mentally ill. It is believed that the stone is able to get rid of lingering melancholy moods, balance emotions, protect against rash acts and even suicide.
Healers recommend that you always carry this stone with you, and the purer and more transparent the orthoclase, the higher its influence. In addition, there is an opinion about the beneficial effect on the general condition of the body in the treatment of cancer. The stone has the ability to enhance the effect of medications that destroy cancer cells. It does not directly affect tumor growth, but helps to reduce the level of toxic effects of drugs, thus allowing you to increase their dosage and concentration.
It is believed that an orthoclase ring is a great gift for a creative person: a stone helps to catch inspiration, add color to the expression of thoughts, and avoid a creative crisis.
Sunstone helps fight allergies, sanidine helps with asthma and swelling. Adularia is used in the treatment of the genitourinary system and hormonal disorders.
Magical Properties
All types of orthoclase are used in love magic: for example, a moonstone given to young people on their wedding day is able to maintain a happy union for a long time. It will retain its color until there is a threat of destruction of the marriage. Sometimes orthoclase allows you to add a spark to a relationship that has cooled down.
It is most convenient to wear a stone in a pendant, beads, bracelets, so it will save you from separation, save love. A stone will not help to bewitch a person, but it can put things in order, open the soul, arouse interest in itself.
Sun stone can push for action, reward with the gift of clairvoyance. Sanidin will help you win the love and affection of others.
Orthoclase is the talisman-patron of the zodiac signs Cancer and Pisces, in relation to them his action is especially strong, he helps them to find balance, develop intuition. Negative interaction is possible on representatives of the elements of fire: Sagittarius, Lviv, Aries.
