Mica Lepidolite 1 Piece 26-45 gr - cm 3-4.5 Raw Minerals Stones Rocks for Collection.
Phyllosilicate Aluminum.
Also available in lots and in lamellar or mammillary form, at this link, or the Mica Muscovite.
Micas are a group of minerals belonging to the subclass of Phyllosilicates.
Micas are characterized by a layered structure and perfect flaking. These minerals generally crystallize in the monoclinic crystal system, with a tendency to form tabular crystals with lozenge or hexagonal cross-sections and assume pseudo-orthombic or pseudo-hexagonal morphologies.
Structurally micas can be classified as di-octahedral and tri-octahedral. Di-octahedral micas include common micas and
Muscovite, while tri-octahedral micas include
Biotite and
Lepidolite. Both di-octahedral and tri-octahedral micas if fine-grained can be called clayey micas. Micas commonly contain 4-5% by weight of H2O, but are neither fat soluble nor water soluble.
All micas have the same spatial organization of the atoms, this means that their characteristics (such as perfect cleavage) are common to the whole group.
It is hypothesized that the term "mica" derives from the Latin micare or "to shine", in reference to the brilliant appearance of these minerals or from mica, "briciola", since they crumble easily.
Particularly widespread micas in nature are Muscovite and Biotite which participate in the constitution, for example, of granite. In Italy we find deposits in Veneto, Tuscany, Elba, Lombardy and Piedmont. India, Canada and the USA are the countries of greatest production of micas.
Micas are excellent thermal and electrical insulators. An example is Muscovite, as it has many uses in industry as an insulator, although currently it tends to be replaced by synthetic materials.
Generally, micas made up of large and transparent sheets have industrial applications; on the other hand, those in thinner leaves are used for lampshades, stove doors, protective glasses, lamp tubes and for various electrical instruments, given the resistance of this mineral to heat. Furthermore, pressed mica plates are used in the construction of greenhouses, instead of glass.
Micas are mainly used in decorative cosmetics. These minerals can be mixed together to obtain a large variety of colours, with the aim of decorating cards and trinkets.
Some manufacturers of toothpastes use white mica powder, exploiting its slight abrasive effect to clean the surface of the teeth.
The term
Lepidolite derives from the Greek lepidos and lythos, which mean respectively: scale and stone. Lepidolite occurs in spheres made of crystalline flakes and rare tabular crystals or in white, pink or lilac hexagonal-contoured lamellae. Lamellar aggregates are frequent. It is soft and light, perfectly flaky in flexible and elastic lamellas, translucent with a pearly sheen. Easily melts, coloring the flame crimson for the presence of lithium, into an opaque white glass. It is insoluble to acids.
It is formed in lithiniferous pegmatites and in the geodes of some greisen, associated with spodumene, ambligonite, tourmaline and other minerals. It was invented in Australia, USA, Russia, Moravia and Sweden. In Italy, small crystals were found in San Piero in Campo on the Island of Elba.
Despite its rarity, this mineral is the main source of lithium.
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