Mica sheet is an important component of melange.

Mica is a kind of rock forming mineral with hexagonal lamellar crystal shape and is one of the main rock forming minerals. Mica crystal has a layered structure inside, so it is lamellar crystal, mainly hexagonal lamellar crystal. Characteristics are insulation, high temperature resistance, the most used in industry is sericite, widely used in paint, paint, electrical insulation and other industries.

Mica is a kind of rock forming mineral with hexagonal lamellar crystal shape and is one of the main rock forming minerals. Mica crystal has a layered structure inside, so it is lamellar crystal, mainly hexagonal lamellar crystal. Characteristics are insulation, high temperature resistance, the most used in industry is sericite, widely used in paint, paint, electrical insulation and other industries.

A geological, mineralogical, and geochemical characterization of the Tamame de Sayago (Zamora, Spain) deposit was carried out with the aim of knowing the conditions that facilitated the genesis in the same deposit of kaolinite and smectites. The alteration processes affecting a Variscan granite were deduced throughout the study of a very wide group of representative samples by X-ray diffraction (XRD), scanning electron microscopy (SEM), chemical analyses of major, minor, and trace elements, as well as δ18O, δ34S stable isotope and K/Ar dating analyses. In addition, 2D and 2.5D graphs of the kaolinite and smectite isoconcentrations were obtained from core data. According to the color and texture, two different clayey rock types were identified and named as homogeneous alteration zones (ZAHO) and heterogeneous alteration zones (ZAHE). The ZAHO are regoliths in which the granite texture is preserved, and the feldspars are almost completely kaolinized. In the ZAHE, the original texture of the granitic rock is lost, and the main clay mineral is smectite. The mineralogical composition is similar, with kaolinite, smectite, mica, quartz, scarce feldspar, and occasionally natroalunite and APS (aluminum-phosphate-sulphate); however, the mineral concentration varies considerably because ZAHO are rich in kaolin areas whereas ZAHE are bentonitic areas. Both rock types contain numerous veins and nodules. The weathering of the Paleozoic granite alongside the absence of sedimentation during the Mesozoic led to the formation of kaolinite that is preserved in ZAHO materials. Nonetheless, during the Cretaceous–Tertiary transit, the conditions of tectonic stability varied. Late Variscan faults reactivated which allowed the percolation of Mg- and Ca-rich hydrothermal fluids through the already kaolinized granite, increasing the alteration of the primary silicates and leading to the formation of smectites in ZAHE materials. The amount of smectites is greater closer to the faults. The stable isotopes indicate the meteoric nature of the low-temperature hydrothermal fluids. The K/Ar data obtained from the natroalunite of veins indicate that those hydrothermal fluids circulated in different pulses from 66.4 ± 1.7 to 58.8 ± 1.5 Ma, as a minimum. Those ages are coincident with the first formation stages of the Duero Basin.

When searching for effective skincare ingredients, the ground may not be the first place that comes to mind. But, clays (which are essentially types of dirt) are well known for their amazing cleansing and purifying properties. Natural clays have been used on the skin for centuries, and continue to be a popular ingredient in products today.In general, clays are soft, fine-grained mineral substances. There are different types of clay which vary in composition depending on the origin. While the properties of each clay varies, they are most commonly used in skincare because of their absorption properties. When applied, clay pulls oil from the skin, leaving it balanced and clean.Depending on your skin type, one clay may be better suited for your skin than another. For example, kaolin clay is a fine-grained clay with mild absorption properties, which makes it better for dry to normal skin. On the other hand, French green clay and bentonite clay have stronger absorption properties, making them a good fit for oily skin.

Kaolin and bentonite (nanoclay NM-600) are nanostructured aluminosilicates that share a similar chemical composition, platelet-like morphology, and high binding capacity for biomolecules. To investigate if these material-based criteria allow for a common grouping, we prepared particle suspensions of kaolin and bentonite with a similar hydrodynamic diameter and administered them to NR8383 alveolar macrophages in vitro and also to a rat lung using quartz DQ12 as a reference material. Bentonite was far more bioactive in vitro, indicated by a lower threshold for the release of enzymes, tumor necrosis factor α, and H2O2. In addition, in the lung, the early effects of bentonite exceeded those of kaolin and even those of quartz, due to strongly increased numbers of inflammatory cells, and elevated concentrations of total protein and fibronectin within the bronchoalveolar lavage fluid. The pro-inflammatory effects of bentonite decreased over time, although assemblies of particle-laden alveolar macrophages (CD68 positive), numerous type-2 epithelial cells (immunopositive for pro-surfactant protein C), and hypertrophic lung epithelia persisted until day 21. At this point in time, kaolin-treated lungs were completely recovered, whereas quartz DQ12 had induced a progressive inflammation. We conclude that bentonite is far more bioactive than equally sized kaolin. This argues against a common grouping of aluminosilicates, previously suggested for different kaolin qualities.Keywords: nanotoxicology, aluminosilicate, alveolar macrophage, intratracheal instillation

Natural clays have been used to heal skin infections since the earliest recorded history. Recently our attention was drawn to a clinical use of French green clay (rich in Fe-smectite) for healing Buruli ulcer, a necrotizing fasciitis (‘flesh-eating’ infection) caused by Mycobacterium ulcerans. These clays and others like them are interesting as they may reveal an antibacterial mechanism that could provide an inexpensive treatment for this and other skin infections, especially in global areas with limited hospitals and medical resources.Microbiological testing of two French green clays, and other clays used traditionally for healing, identified three samples that were effective at killing a broad-spectrum of human pathogens. A clear distinction must be made between ‘healing clays’ and those we have identified as antibacterial clays. The highly adsorptive properties of many clays may contribute to healing a variety of ailments, although they are not antibacterial. The antibacterial process displayed by the three identified clays is unknown. Therefore, we have investigated the mineralogical and chemical compositions of the antibacterial clays for comparison with non-antibacterial clays in an attempt to elucidate differences that may lead to identification of the antibacterial mechanism(s).The two French green clays used to treat Buruli ulcer, while similar in mineralogy, crystal size, and major element chemistry, have opposite effects on the bacterial populations tested. One clay deposit promoted bacterial growth whereas another killed the bacteria. The reasons for the difference in antibacterial properties thus far show that the bactericidal mechanism is not physical (e.g., an attraction between clay and bacteria), but by a chemical transfer or reaction. The chemical variables are still under investigation.Cation exchange experiments showed that the antibacterial component of the clay can be removed, implicating exchangeable cations in the antibacterial process. Furthermore, aqueous leachates of the antibacterial clays effectively kill the bacteria. Progressively heating the clay leads first to dehydration (200°C), then dehydroxylation (550°C or more), and finally to destruction of the clay mineral structure by (~900°C). By identifying the elements lost after each heating step, and testing the bactericidal effect of the heated product, we eliminated many toxins from consideration (e.g., microbes, organic compounds, volatile elements) and identified several redox-sensitive refractory metals that are common among antibacterial clays. We conclude that the pH and oxidation state buffered by the clay mineral surfaces is key to controlling the solution chemistry and redox related reactions occurring at the bacterial cell wall.

Of the 28 known species of the mica group, only 6 are common rock-forming minerals. Muscovite, the common light-coloured mica, and biotite, which is typically black or nearly so, are the most abundant. Phlogopite, typically brown, and paragonite, which is macroscopically indistinguishable from muscovite, also are fairly common. Lepidolite, generally pinkish to lilac in colour, occurs in lithium-bearing pegmatites. Glauconite, a green species that does not have the same general macroscopic characteristics as the other micas, occurs sporadically in many marine sedimentary sequences. All of these micas except glauconite exhibit easily observable perfect cleavage into flexible sheets. Glauconite, which most often occurs as pelletlike grains, has no apparent cleavage.

Mica is a mineral name given to a group of minerals that are physically and chemically similar.  They are all silicate minerals, known as sheet silicates because they form in distinct layers.  Micas are fairly light and relatively soft, and the sheets and flakes of mica are flexible. Mica is heat-resistant and does not conduct electricity.  There are 37 different mica minerals. The most common include: purple lepidolite, black biotite, brown phlogopite and clear muscovite.

Micas (/ˈmaɪkəz/ MY-kəz) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is common in igneous and metamorphic rock and is occasionally found as small flakes in sedimentary rock.[6] It is particularly prominent in many granites, pegmatites, and schists,[7] and "books" (large individual crystals) of mica several feet across have been found in some pegmatites.[8]Micas are used in products such as drywalls, paints, fillers, especially in parts for automobiles, roofing and shingles, as well as in electronics. The mineral is used in cosmetics and food[9] to add "shimmer" or "frost."

Mica is an ingredient used widely in the cosmetics industry. We look at which companies are using illegally sourced mica in their makeup, and the links with child labour in many mica mines.   Mica is the name of a naturally occurring group of silicate minerals. It is derived from the Latin word micare which means to shine, to flash or to glitter. Mica is used throughout the cosmetics and personal care industry, and is common in makeup like eye shadow and lipstick and other products that glow or shine.It can be listed as ‘mica,’ ‘potassium aluminium silicate,’ or ‘CI 77019,’ on ingredient lists.Mica is also mined for industries including pharmaceuticals, electronics, construction, and is used in things like car paint.However, there are several problems with mica, including the health impact on workers mining it, and child labour.

Some mica mines provide no protection, support, or any kind of safety measures for the children – some as young as 5 years old – or the adults who work in the mines. Brutally harsh conditions and extremely long days in the hot sun are some of the things that wait for the people that work there.  Small children are forced to go down the narrow shafts, some as much as 15-30 metres deep to get to the mica that the adults can’t reach. Cuts, broken bones, serious injury, and at times death are all part of the everyday risks they are forced to take due to unstable mineshafts and injuries from the tools used. Many children have died and seen their family members die on the mines. All for just a wage of between 25-50c (USD) per day, depending on how much they can dig up. 1kg of mined mica will get the miners 8c (USD) but will get $1000 (USD) on the international market. As consumers, you all have the power to demand ethical transparency from the brands you use and support. Raising awareness and asking questions about sourcing and ingredients will start important conversations and force brands to raise their awareness and their ethical game. 

Mica is a naturally occurring, highly platy phyllosilicate of aluminium and potassium that occurs in book-like form that can be easily split into extremely thin, often transparent sheets that are both tough and flexible. Mica is fairly widespread and occurs in igneous, metamorphic and sedimentary rocks. Large mica crystals are typically mined from granitic pegmatites. Only very few crystals are industrially mined. Muscovite white mica is the most common commercial form, accounting for 90 % of global consumption, followed by phlogopite, a bronze-colored variety. Mica is unique among platy minerals due to the broad range of particle sizes naturally available from microns up to several centimeters and even meters!Imerys mines and processes both muscovite and phlogopite mica to serve the plastics, paints, ceramics, sound-damping and cosmetics markets.

White clay or kaolin is a rock powder originally discovered in China on the Kao-ling hill with multiple uses thanks to its multiple properties and versatility. Initially it was used for therapeutic purposes, but its magnificent properties extended its use to a cosmetic level as well. In the cosmetic environment it is used as an ingredient thanks to its multiple benefits, among which its purifying, calming and revitalizing effect stands out. Furthermore, among the benefits of white clay, you knew that it is suitable for all skin types and also has a pH very similar to that of our skin. Surely you already know that there are countless types of clay such as green, red, pink and black. But we are going to focus on the white one because this product has proven very useful in fighting very common skin problems.

The name of kaolin clay comes from the French kaolin, in turn from the Chinese kao-ling shan 高岭山, this is the name of a mountain (shan 山 means mountain) in the province of Jianxi, towards the east of China, a This area is also known as Porcelain Land. Hence it also receives the English name "China clay". Although its name comes from this first location, there are obviously deposits of this white stone in many other parts of the world (eg in Africa it is called Kalaba).It is one of the most appreciated materials used in ceramics , luckily it is relatively abundant in the Earth's crust. You can imagine its age..., depending on the sources that talk about this material and its sites, various ages are considered, but the vast majority of them are no less than 100 million years old.

If you haven't heard of kaolin , but you have oily skin and you constantly have to worry about breakouts, blackheads or shiny areas in your daily life, then you should know this ingredient that can save you a lot of bad times. It is also a basic that is already included in many of the products we use for aesthetic purposes. In search of healthy skin with beauty products, we can try many alternatives until we find what suits our face best, which tends to vary for many reasons, especially genetics. Clay masks , for example, have proven to be wonderful in this sense, and the importance lies in choosing the right one for each type. 

provides a layer of protection against ultraviolet rays and controls pests that affect crops and decorative plants. It stands out for its  purity, white color  and its  easy dispersion in water , making it an ideal product to spray and attack aerial pests (flies, mosquitoes). Here you can buy 100% pure and natural kaolin  from the Bioky brand, especially recommended for small-scale agriculture and crops.Specifically, kaolin is an aluminum silicate, a soft, plastic clay, composed of fine-grained lamellar particles. Its texture is a  very fine micronized powder  that makes it easy to apply. Thanks to its benefits, it is a product that is booming and offers a large number of benefits, both for obtaining safe raw materials and for guaranteeing the production of organic crops.At a regulatory level, according to Regulation (EC) No. 1107/2009 of the European Parliament and of the Council , kaolin (aluminum silicate) is considered a conventional and low-risk active substance . Its function is as an insect repellent . In addition, this product can be applied for phytosanitary protection in the field of Organic Agriculture, as dictated by Implementing Regulation 2021/1165 .

China was precisely the first country to use white clays in ceramics and in the 16th century it acquired great fame in the manufacture of porcelain among the Western nobility of the time. Therefore, its industrial use has always been very important throughout the world.This mineral is extracted from a mining operation and once extracted it must go through a beneficiation process to obtain washed kaolin as an industrial raw material.Kaolin is very versatile due to its qualities, not only industrial but also medicinal and healing when ingested. Although the most important application of kaolin is in the paper industry as a filler or coating pigment. In fact, estimates suggest that 45% of the total kaolin produced is destined for this industry. The rest is distributed between the production of ceramics, refractory products, paints and varnishes; creation of polymers and fiberglass, manufacture of pesticides and fertilizers and to a lesser extent, for the production of cosmetics .

Mica, a mineral that has been used for centuries, is not just a pretty face; it's a versatile material with a rich history. Mica Powder, derived from this natural gem, adds a touch of glamour to various applications, from cosmetics to construction.

HighlightsTwo-phase olive mill waste was used to produced activated hydrochars.The physical activated sample resulted to be the most promising option.Doping carbons with nitrogen does not appear to enhance their adsorption capacity.