60 Buddington — Natural and Synthetic Melilites. 



Table IX. 



Optical and thermal data for mixtures of 10 percent 3Na 2 O.Al 2 3 .3Si0 2 with 

 varying percentages of 2CaO.Mg0.2Si0 2 and 3CaO.Fe20 3 .3Si0 2 . 



Compositions in weight percent. 



3Na 2 0. 



2CaO. 



3CaO. 







One Crystals 



Glass + 





A1 2 3 . 



MgO. 



Fe 2 3 . 







crystal -f- trace 



trace of 





3Si0 2 



2Si0 2 



3Si0 2 



nco 



Tie 



phase of glass 



crystals 



All glass 



10 



90 



00 



*1.632 



*1.635 



Inhomogeneous 

 (40hrs.atl000°) 



1391° 



1358° 



10 



82 



8 



*1.639 



*1.639 



Inhomogeneous 

 (40hrs.atl000°) 







10 



75 



75 







Inhomogeneous 

 (40hrs.atl000°) 







10 



67.5 



22.5 



1.654 



1.644 



1164° 1170° 

 ( 1 /2hr.)( 1 / 2 hr.) 



1352° 



1357° 



10 



54 



36 



1.675 



1.653 



1145° 1160° 

 (40hrs. )(y 2 hr.) 



1325° 



1330° 



10 



45 



45 



1.688 



1.658 



1145° 1162° 

 (15hrs.)(y 2 hr.) 



1305° 



1309° 



10 



36 



54 



*1.699 



*1.662 



Inhomogeneous 

 (40hrs.atl000°) 



1284° 



1290° 



10 



18 



72 







Inhomogeneous 

 (2hrs.atl070°) 



1235° 



1240° 



10 



00 



90 







Inhomogeneous 

 (2hrs.atl070°) 



1235° 



1244° 



Determined on dominant crystal phase. 



Table X. 



Optical and thermal data for mixtures of 10 percent 3Na20.Al 2 3 .3Si0 2 with 



varying percentages of 2CaO.Mg0.2Si0 2 and 3CaO.Al 2 3 .3Si0 2 . 



Compositions in weight percent. 



3Na 2 0. 



2CaO. 



3CaO. 







One Trace of 



Glass -f- 





A1 2 3 . 



MgO. 



A1 2 3 . 







crystal disso- 



trace 





3Si0 2 



2Si0 2 . 



3Si0 2 . 



nco 



fte 



phase ciation. 



crystals 



All glass. 



10 



90 



00 



*1.632 



*1.635 



Inhomogeneous 



1391° 



1398° 



10 



63 



27 



*1.632 



*1.630 



Inhomogeneous 



1360° 



1367° 



10 



50 



40 



1.630 



1.628 



1130° 1150° 

 (lhr.)(l hr.) 







10 



45 



45 



1.630 



1.628 



1140° 1160° 

 (lhr.)(l hr.) 



1334° 



1340° 



10 



27 



63 



1,631 



1.625 



1165° 1185° 

 (lhr.)(l hr.) 



1317° 



1324° 



10 



9 



81 



1.633 



1.621 



1125° 



1327° 



1334° 



(16hrs.) 

 * Determined on dominant crystal phase. 



