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Sir George Gabriel Stokes was an Irish mathematician and physicist. He was born in 1819 at Skreen and died in 1903. It is to Sir George Stokes that the modern theory of viscous fluids and the discovery that rays beyond the violet end of the spectrum produce fluorescence in certain substances is due.
 Research George Stokes
Alpha Rays are a stream of swiftly moving alpha particles. An alpha ray is capable of ionising gases and of producing fluorescence in certain substances.
Research Alpha Rays
Anthracene is a complex hydrocarbon contained in coal-tar, and obtained from the highest-boiling portion of the tar,
namely the so-called 'green grease', which forms the last portion of the heavy oil or dead oil resulting in the fractional distillation of the tar. Anthracene is a commercial product of some importance, as a source of alizarine and numerous other dyes of a similar kind. The commercial product forms a hard crystalline cake containing some 50 percent of anthracene; when pure it crystallizes in the form of glistening, white plates showing a bluish-violet fluorescence, and has neither taste nor smell. Several colours used in dyeing are known as 'anthracene colours'.
Research Anthracene
Eosin is one of the coal-tar colours, the potassium or sodium salt of tetrabromo-flourescein. It is a red substance which possesses brilliant fluorescence in alkaline solution. It is used in acid solution as a red dye for wool and silk and is also used in red ink.
Research Eosin
Fluorescein is an organic dye compound obtained by heating together pthalic anhydride and resorcinol. It is a red powder insoluble in water, but it dissolves in alcohol and also in alkalis, giving a brilliant green fluorescence.
Research Fluorescein
Fluorescence is the process of emission of electromagnetic radiation resulting from the absorption of certain types of energy. Fluorescent paints are usually the sulphides of calcium, barium and strontium which glow in the dark after having been exposed to light for a while.
Research Fluorescence
Adamite is a rare mineral with a brilliant fluorescence, it is of scientific interest and is much desired by collectors for its bright colours and general attractiveness, but has no industrial use. It has the formulae Zn2(AsO4)(OH) and a relative hardness of 4. Adamite was discovered by the French mineralogist Gilbert-Joseph Adam at Chanarcillo, Chile during the 19th century, and the mineral was confirmed as a distinct species in 1886 and named after its discoverer.
Research Adamite
Autunite is a secondary mineral found in the zone of oxidation and weathering of uranite or other uranium minerals. It has strong fluorescence and is used as an ore of uranium. It has the formulae Ca(UO2)2(PO4)2ù10- 12H2O and a relative hardness of 3.
Research Autunite
Scapolite has the formulae (Na,Ca,K)4A13(Al,Si)3Si6O24(Cl,SO4,CO3) and a relative hardness of 6. It shows fluorescence. Occurs in the crystalline schists, gneisses, and often is probably derived from the alteration of plagioclase feldspars. Also occurs in crystalline limestones formed by metamorphic contact or igneous intrusion. Associated with diopside, amphibole, garnet, apatite, and zircon.
Research Scapolite
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The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
©1993 - 2009 The Probert Encyclopaedia
Southampton, United Kingdom
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