It is recorded that interest in the commercial mining of fluorspar began in 1928 with the first ore being extracted in 1933. Neither does all fluorite fluoresce equally brightly, even from the same locality. The Inhabitants Are Mainly Engaged In The Fishing ...Foil IFoil. [22], George Gabriel Stokes named the phenomenon of fluorescence from fluorite, in 1852. The Scientific Aspect Of Human Food Is Dealt With Under Nutrition; Diet And Dietetics. The Name Angus Was Officially Adopted ...ForfeitureForfeiture, In Law, The Termination Of A Right ; The Loss Or Liability To The Loss Of Property In Consequence Of An Offence Or Breach Of Contract ; It Is Also Applied To The Property Of Which The Party Is Deprived. Pop. Ask your question. (see Ci.oud.) By using combinations of different types of glass, lens manufacturers are able to cancel out or significantly reduce unwanted characteristics; chromatic aberration being the most important. Above Sea-level. Hydrogen fluoride is liberated from the mineral by the action of concentrated sulfuric acid: The resulting HF is converted into fluorine, fluorocarbons, and diverse fluoride materials. Forchheim Was The Residence Of The Carolingian Sovereigns, Including Charle Magne, In The 9th Century. W. Of Chicago, Served By The Chicago, Aurora And Elgin, The Chicago Great Western And The Soo Line Railways. Log in. The structural motif adopted by fluorite is so common that the motif is called the fluorite structure. USES: Fluxing agent. Telescope Optics Evaluation and Design. The highest grade, "acid grade fluorite" (97% or more CaF2), accounts for about 95% of fluorite consumption in the US where it is used to make hydrogen fluoride and hydrofluoric acid by reacting the fluorite with sulfuric acid. As Food Material In Its Natural State Only Keeps Sound And Edible For A Comparatively Short Time, Its Preservation Has Engaged The Attention Of Mankind From The Very Earliest Times And Has Been Practised From The Dawn Of Civili Zation. Its Existence Implies A Certain Complexity Of Development In The Social Order, And A Distinction Based, More Or Less Roughly, On This Complexity. The Population Of The World Is Believed To Be About 1,800,000,000. [2] Currently, the word "fluorspar" is most commonly used for fluorite as the industrial and chemical commodity, while "fluorite" is used mineralogically and in most other senses. (town), 37,993 (commune). Alumina is dissolved in a bath that consists primarily of molten Na3AlF6, AlF3, and fluorite (CaF2) to allow electrolytic recovery of aluminium. Lenses made with fluorite are superior to fluoro-crown based lenses, at least for doublet telescope objectives; but are more difficult to produce and more costly.[31]. Pop. Acts Viii. This Genus Is Confined To The Tropi Cal Regions Of The Eastern Hemisphere And Australia. The First Food Controller Was Viscount Devonport, Succeeded In Turn By Lord Rhondda And Others. Pop. : 7789-75-5. Steam, Gas, Oil And Petrol Engines, Air-compressors, Pumps And Some ...FocaFoca, A Town Of Bosnia, Yugoslavia. Fluorspar Fluorspar Derives Its Name From Its Use In Metallurgical Operations As A Flux (cf. In The United States ...Food CouncilFood Council. The Lower Lobe Of The Caudal Fin Is Very Long And, With Strong Strokes Of The Tail, These Fishes Emerge Rapidly From The Water And, With The Pectoral Fins Outspread, ...Flying Fox OrFlying-fox Or The Name Applied To The Fruit-eating Bats Of The Genus Pteropus, Which Contains More Than Half The Family Pteropidae. The Word Was Coined By W. J. Thoms In 1846 To Denote The Traditions, Customs And Superstitions Of The Uncultured Classes In Civilized Nations. Ask your question. ...FormeretFormeret, An Architectural Term For The Rib Of A Gothic Vault That Connects Adjacent Piers On The Same Side Of The Nave Or Aisle, And Forms An Arch In The Plane Of The Wall; A Wall-rib (see Vault). The Early ...FootscrayFootscray, A Suburb Of Melbourne, Australia, On The Salt Water River. His Doctrines Were Largely Adopted In The Frankfurter ...Foreign OfficeForeign Office, In Great Britain, That Department Of The Executive Which Is Concerned With Foreign Affairs. ), May-fly (q.v. In Early Usage The Word Was Confined To Dried Forage As Opposed To Grass. I0,346. Fluere, To Flow, And Its Ger. It is a solid mineral and is found in yellow, green, pink, blue, purple, colorless, and sometimes black. Optically clear transparent fluorite lenses have low dispersion, so lenses made from it exhibit less chromatic aberration, making them valuable in microscopes and telescopes. From which fluoride can be extracted. Designations: Calcium fluoride is a mineral composed of CaF2. Element substitution for the calcium cation often includes certain rare earth elements (REE), such as yttrium and cerium. //-->. [34] The fluorite also serves to correct optical aberrations in these lenses. The relative density is 3.18, the melting point is 1423ºC, boiling point is about 2500 ºC. Of Scranton. The color of visible light emitted when a sample of fluorite is fluorescing depends on where the original specimen was collected; different impurities having been included in the crystal lattice in different places. ); Also A Conical Cap Worn By Dunces. The Flute Family Is Classified According To The Type Of Mouth Piece Used, I.e., (i) Those With The Simple ...FluxFlux, In Metallurgy, A Substance Introduced In The Smelting Of Ores. Fluorite is also used as a flux in the manufacture of steel and other metals to eliminate impurities.There is a great demand for Fluorite in the optics field, and to meet it synthetic crystals are grown to produce special lenses. Similar Local Winds Occur Elsewhere, E.g., Norway, Green Land And North America. Fluorite also exhibits the property of thermoluminescence.[26]. Connecting At Orbliston Junction With The Main Line From Elgin To Keith. From The Revolu Tion Until That Time There Had Been Only Two Secretaries ...ForeshoreForeshore, That Part Of The Seashore Which Lies Between High And Low Water Mark At Ordinary Tides. Mining still takes place in Blue John Cavern and Treak Cliff Cavern. Pop. Name Muss-spat). The Population Of The Commune In 1931 Was 60,824. Fluorite is the only mineral for which significant quantities of the important element fluorine can be obtained. It Lies At The East End Of The Loch Of Forfar In The Valley Of Strath More, And Is 13 M. N. By E. Of Dundee By Road And 214 M. By The L.m.s.r. The Population Was 10,768 In 1920 And Was 14,555 In 1930. Every color of the rainbow in various shades is represented by fluorite samples, along with white, black, and clear crystals. It Comprises Numerous Species, A Considerable Proportion Of Which Occur In The Islands Of ...Flying SquirrelFlying-squirrel, The Name Applied To Two Very Differ Ent Groups Of Rodents, In Both Of Which A Parachute-like Expansion Of The Skin Of The Flanks Enables Them To Take Long Flying Leaps From Tree To Tree. Ionic gallium has a 3+ (Ga3+) charge, and the Oxide ion has a 2- (O2-) charge. Frites for enamels, etc. Its Industries Include The Manufacture Of Tiles And Pasteboard Wares, While There Are Coal Mines In The ...ForbesForbes, A Municipal Town Of Ashburnham County, New South Wales, Australia, 289 M. W. By N. From Sydney, On The Lachlan River, And With A Station On The G.w. It contains 58.21 parts of calcium. [11], The world reserves of fluorite are estimated at 230 million tonnes (Mt) with the largest deposits being in South Africa (about 41 Mt), Mexico (32 Mt) and China (24 Mt). Fundi), Province Of Rome, 12 M. N.w. It Is Delightfully Situated On The Spey About 9 M. E. By S. Of Elgin, The Terminus Of A Branch Of The L.m.s.r. [30] The refractive qualities or fluorite and of certain flint elements provide a lower and more uniform dispersion across the spectrum of visible light, thereby keeping colors focused more closely together. It has wide range of application but mostly used in foundry industry. Is Most Readily Prepared By Passing The Vapour Of Methyl Alcohol, Mixed With Air, Over Heated Copper Or Platinum ; The Formaldehyde Vapour Is Condensed And Absorbed, Either In Water Or Alcohol. [21], Recently discovered deposits in China have produced fluorite with coloring and banding similar to the classic Blue John stone. One fluorescent variety of fluorite is chlorophane, which is reddish or purple in color and fluoresces brightly in emerald green when heated (thermoluminescence), or when illuminated with ultraviolet light. Fluorite can also be found as a constituent of sedimentary rocks either as grains or as the cementing material in sandstone. google_ad_width = 728; In the St. Lawrence area, the veins are persistent for great lengths and several of them have wide lenses. It was previously thought that fluorine gas did not occur naturally because it is so reactive and would rapidly react with other chemicals. Copyright © 2011 VinDaj, Inc. – All Rights Reserved, Encyclopedia-britannica-volume-9-part-1-extraction-gambrinus. It Comprises An Area Of 32 Sq.m. Into A Hard Elastic Mass Insoluble In Water. 1. Log in. Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF 2. ), Etc. (193o) 15,807. What Is Fluorite Chemical Formula? To Promote Fluidity, And To Remove Objectionable Impuri Ties In The Form Of A Slag. Fluorite has a uniquely high transparency at this wavelength. CaF₂ ... One of the largest deposits of fluorspar in North America is located in the Burin Peninsula, Newfoundland, Canada.