54 Buddington — Natural and Synthetic Melilites. 



50 2CaO.ALO,SiO 2 -30 2CaO.Mg0.2Si0 2 - 20 j *> ^ZSI 



Temperature Time Phases 



1100° 16 hrs. Homogeneous fibrous granular and radiating 



sperulitic aggregate, Ww = 1.650 ne = 1.645 



1200° • 1 hr. Homogeneous fine fibrous aggregate. 



1210° 1 hr. Coarse laths and trace of glass. 



1280° 16 hrs. Crystals plus little glass. 



1478 1/3 hr. Glass plus trace crystals. 



1484° 1/3 hr. All glass. 



50 2CaO.Al 2 O,SiO 2 -10 2CaO.MgO.2SiO. - 40 { JJ ^SS 



Temperature Time Phases 



1150° 1 hr. Very fine fibrous homogeneous aggregate. 



1175° 1 hr. Trace of beginning of dissociation. 



%j — 1.650 n e = 1.644 

 1290° 40 hrs. Crystals plus little glass. 



n<a = 1.655 n € = 1.649 



40 2CaO.Al 2 O,SiO 2 -40 2CaO.Mg0.2SiO a - 20 { *> ^OALoS 



Phases 

 Homogeneous single crystal phase. 



%= 1.648 n e = 1.645 

 Trace of beginning of dissociation. 

 Glass plus trace of crystals. 

 All glass. 



Temperature 



Time 



1175° 



1 hr. 



1185° 

 1446° 

 1450° 



1 hr. 

 1/3 hr. 

 1/3 hr. 



40 2CaOAl 2 3 .Si0 2 — 



Temperature 

 1110° 



Time 

 1 hr. 



Phases 

 Homogeneous single crystal phase. 

 na = 1.645 ne = 1.640 

 1140° 1 hr. Distinct trace of dissociation. 



30 2CaO.MO,SiO s -40 2CaO.MgO.2SiO a -30 {»<> ^^ofsliO, 



Phases 



Homogeneous single crystal phase. 

 Homogeneous aggregate of coarse plates and 



laths. 



ww = 1.644 ne= 1.641 

 Trace of dissociation. 

 Little dissociation. Minor phase as strong bire- 



fringent rods and interstitial. 

 Glass plus trace of crystals. 

 All glass. 



Temperature 



Time 



900° 

 1175° 



18 hrs. 

 1 hr. 



1220° 

 1250° 



1 hr. 

 1 hr. 



1419° 

 1423° 



1/3 hr. 

 1/3 hr. 



20 2CaO.Al 2 ; 



3 .Si0 2 — ( 



Temperature 

 1200° 

 1205° 



Time 



2 hrs. 

 40 hrs. 



60 2CaO.MgO.2SiO, - 20 { »g ^tffioS, 



Phases 

 Homogeneous. Ww = 1.641 ne = 1.641 

 Trace of dissociation. 



