62 Buddington — Natural and Synthetic Melilites. 



Table XIII. 



Optical characters and thermal data of mixtures containing 10 percent 



3Na 2 O.Al,0 3 .3Si0 2 and 20 percent 2CaO.Al 2 3 .Si0 2 with varying 



percentages of 2CaO.Mg0.2Si0 2 and 3CaO.Fe 2 3 .3Si0 2 . 



Compositions expressed in weight percent. 



All 



I 



3NaX>, 



. 2CaO 



. 2CaO. 



. 3CaO. 



One Crystals 



Glass -}- 



A1 2 3 . 



AloOc 



, MgO 



. Fe 2 3 . 



crystal -j- Trace 



Trace 



3Si0 2 



Si6 2 



2Si0 2 



3Si0 2 n-u n e 



phase, of glass. 



crystals. 



10 



20 



70 



00 Inhomogeneous 

 (2hrsatl050°) 







10 



20 



56 



14 Inhomogeneous 

 (lhr.at 1176*) 







10 



20 



46 



24 inhomogeneous 

 (lhr.at 1151°) 







10 



20 



35 



35 *1.679 *1.666 

 (16hrs.atll50° 



Trace of 

 ) Inhomogeneity 



1298° 



10 



20 



28 



42 1.689 1.669 



1177° 1191° 

 (2hrs.)(2hrs.) 



1278° 



10 



20 



17.5 



52.5 1.694 *1.673 



Inhomogeneous 

 (40hrs.atll60°) 





10 



20 



10.5 



59.5 *1.711 *1.684 



Inhomogeneous 





- 









(16hrs. at 1125°) 





1305 c 

 1284 c 



Determined on dominant crystal phase. 



Table XIV. 



Optical characters and thermal data of mixtures containing 10 percent 



3Na 2 O.Al 2 3 .3Si0 2 and 20 percent 2CaO.Al 2 3 .Si0 2 with varying 



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



3Na 2 0. 2CaO. 2CaO. 3CaO. 



One Trace of 



Glass -{- 





A1 2 3 . 



A1 2 3 



.MgO. A1 2 3 . 



crystal disso- 



Trace of 



All 



3Si0 2 



Si0 2 



2Si0 2 3Si0 2 M W n € 



phase. ciation. 



crystals 



glass. 



10 



20 



70 00 Inhomogeneous 

 (2hrs.atl050°) 





•• 



•• 



10 



20 



35 35 Inhomogeneous 

 (2hrs.atl050°) 





•• 



•• 



10 



20 



28 42 1.638 1.633 



1200° 1220° 

 (lhr.)(i/ 2 hr.) 



1380° 



1386° 



10 



20 



17.5 52.5 1.641 1.634 



1130° 1145° 

 (16hrs.)(lhr.) 







10 



20 



00.0 70 1.638 1.624 



1140° 1165° 

 (2hrs.)(lhr.) 







