Guide books of excursions in Canada1-10 . h-red to very palesalmon pink feldspar, which in thin section under themicroscope is seen to be an irregular intergrowth of ortho-clase and albite, the latter, as indicated by the analysis,being the more abundant. Associated with this micro-perthite as accessory constituents, locally and usually insmall amount, are biotite, muscovite, scapolite, calcite,magnetite, hematite (micaceous iron ore), molybdenite,pyrite, pyrrhotite, chalcopyrite, chrysoberyl, spinel andquartz. Although quartz and corundum are commonlysupposed to be mutually exclusive, specime
Guide books of excursions in Canada1-10 . h-red to very palesalmon pink feldspar, which in thin section under themicroscope is seen to be an irregular intergrowth of ortho-clase and albite, the latter, as indicated by the analysis,being the more abundant. Associated with this micro-perthite as accessory constituents, locally and usually insmall amount, are biotite, muscovite, scapolite, calcite,magnetite, hematite (micaceous iron ore), molybdenite,pyrite, pyrrhotite, chalcopyrite, chrysoberyl, spinel andquartz. Although quartz and corundum are commonlysupposed to be mutually exclusive, specimens have beenfound containing these two minerals in small amount. This syenite pegmatite is representative of the finalstages in the crystallization of this highly aluminousmagma. 93 Mr. M. F. Connor has made an analysis of thiscorundum-syenite-pegmatite from Craigmont, Ont., theresults adjusted to a basis of ioo being given under purposes of comparison the analysis of the corundum-syenite-pegmatite, and of the corundum-syenite from. Corundum enclosed in museovite red syenite. Just west of Blue Mountain, Methuen, 56 diam. Bet. crossed nicols. Nikolskaja Ssopka in the Urals, Russia, are included underII and III. (Tschermaks Min. und Pet. Mittheil,.XVIII, 1898, p. 219). Under I (a) is given the analysis ofI, omitting the corundum and adjusting it to a basis of100. Under II (a) and III (a) are similarly includedanalyses of II and III, in which the corundum is neglected 94 and the remaining constituents recalculated to a basis ofioo. Under IV is an analysis of the separated microper-thite from the corundurn-syenite-pegmatite of Craigmont,Ont. Under V is an analysis of a similar feldspar of thecorundum-syenite-pegmatite from Sivamalai, India, [7, ]. — I II III la. Ila. Ilia. IV V Corundum 34-62 40-53 13-62 o-19 0-04 0-67 35-40 40-06 13-65 o-35 18-5552-3416-05 o-45 Si02 A1203 Fe2C»3 FeO 62-30 20-93 0-29 0-06 I -02 9-10 5-231 -07 62-7121-37 o-55 64-65 19-83 0-56 63-
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1913
