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Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It is a halide mineral composed of calcium fluoride. It crystallizes in isometric…

Fluorellestadite is a rare nesosilicate of calcium, with sulfate and fluorine, with the chemical formula Ca10(SiO4)3(SO4)3F2. It is a rare nesosilicate of calcium, with sulfate…

Fluororichterite is a rare amphibole with formula Na(NaCa)Mg5Si8O22F2. It was recognized by the International Mineralogical Association in 1994. Its name is derived from its fluorine…

Triangle is a plane figure with three straight sides and three angles. The three angles always add to 180°. The vertex is a corner of the…

Fluorcaphite is a mineral with the chemical formula (Ca, Sr, Ce, Na)5(PO4)3F. It is a hexagonal-pyramidal mineral containing calcium, cerium, fluorine, oxygen, phosphorus, sodium, and…

Fluorapophyllite is a mineral of the apophyllite group, with the chemical formula of KCa4Si8O20(F, OH)·8(H2O). It is a particular apophyllite mineral with more fluorine than…

Medians of a Triangle A median of a triangle is a line segment joining a vertex to the midpoint of the opposite side. Triangle is…

Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). It is a crystalline mineral, formed from…

Fluor-uvite is a tourmaline mineral with the chemical formula CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3F. It is a rare mineral that is found in calcium-rich contact metamorphic rocks with increased…

Fluor-liddicoatite is a rare member of the tourmaline group of minerals and elbaite subgroup. It forms a series with elbaite and probably also with olenite.…

Fluocerite is a mineral, a cerium, lanthanum fluoride, formula (Ce, La)F3. It is a mineral consisting of a reddish yellow fluoride of cerium and related…

Geometrical Property of Altitudes Sometimes the opposite side isn’t quite long enough to draw an altitude, so we are allowed to extend it to make…