Cilierne

Cilierne is a hypothetical mineral described in this article to illustrate mineral nomenclature and classification. It is proposed to belong to the family of layered aluminosilicate-oxides, with a general composition dominated by aluminum, silicon, magnesium, and iron, and trace amounts of calcium and potassium. The name is derived from a combination of roots meaning hair-like, in reference to the fine, fibrous cleavage reported in some illustrative specimens.

Cilierne crystals are described as tabular to platy, with a vitreous luster and a pale green to gray color. It is said to crystallize in a monoclinic system, with one direction of perfect cleavage and a Mohs hardness of about 5.5 to 6. The estimated specific gravity is 3.1–3.3. It forms in metamorphic environments where aluminosilicate rocks interact with hydrothermal fluids, and is commonly associated with chlorite, biotite, and quartz in the hypothetical sense.

No confirmed natural specimens of cilierne exist, and the mineral is not known to occur in any real locality. It is primarily used in geology education as a teaching example for mineral description, identification methods (X-ray diffraction, electron microscopy), and the conventions of mineral naming.

The name cilierne has appeared in instructional literature to demonstrate how a mineral entry might be structured. See also minerals, aluminosilicates, metamorphic minerals.