84t> Day and Sosman — Melting Points of Minerals. 



Table I. — Principal Temperature Determinations at the Geophysical 



Laboratory, 1905-1910. 









Tem- 





Substance 



Formula 



Transformation 



' pera- j Observer 



Reference 









ture 







Quartz 



Si0 2 



a to /?, and 

 reverse 



575° 



Wright & 

 Larsen 



39, 64 

 (1909-10) 



Aluminum 

 Silicate, 

 (Sillimanite) 



Al 2 SiO f , 



Welting 



1816 



Shepherd 

 & Eankin 



Allen, 

 Wright & 

 Clement 



41, 65 



(1909-10) 



a-Magnesium 



metasilicate 



MgSiO., 



( : 



1554 



13 (1906) 



<( 



a 



" 



1557 



Allen & 

 White 



32 (1909) 



^-Calcium 













metasilicate 

 (Pseudo- 



CaSiO-3 



•' 



1540 



Allen & 

 White 



6 (1900) 



wollastonite) 













a-Calcium 

 orthosilicate 



Ca,SiO., 



" 



2130 



Day & 

 Shepherd 



8, 11, 19 



(1906-7) 



Eutectic between 













a-calcium 



metasilicate 

 and cristoba- 



CaSi0 3 77 %** 

 Si0 2 23 % 



" 



1426 



(< 



it 



lite 













Eutectic between 













a-calcium 

 metasilicate 

 and a-calcium 



CaSi0 3 66 % 

 Ca 2 Si0 4 34 % 



CI 



1440 



i I 



a 



orthosilicate 













Eutectic between 













a-calcium 



Ca 2 Si0 4 93 % 



it 





It 



it 



orthosilicate 



CaO 7 % 





2065 







and lime 













Tricalcium 

 aluminate 



3CaO.Al„O a 



Dissociation into 

 CaO and liquid 



1537 



Shepherd 

 & Eankin 



41, 65 



(1909-10) 



5:3 compound 













of lime and 



5Ca0.3Al 2 3 



Melting 



1382 



t t 



tt 



alumina 











Calcium 



aluminate 



CaO.Al 2 3 



t < 



1592 



it 



ti 



3:5 compound 





Dissociation into 









of lime and 



3Ca0.5Al 2 3 



A1 2 3 and 



1700 



" 



a 



alumina 





liquid 









Eutectic 



3CaO.Al 2 3 9 % 

 5Ca0.3Al 2 3 91 % 



Melting 



1378 



a 



it 



Eutectic 



5Ca0.3Al,0 3 94 % 

 CaO.Al 2 3 6 % 



" 



1378 



tt 



a 



Eutectic 



CaO.Al 2 3 73 % 

 3Ca0.5Al 2 3 27 % 



i i 



1585 



I i 



a 



Magnesium-cal- 

 cium metasili- ' 



MgSi0 3 .CaSi0 3 



u 



1391* 



Day <ft 



46 (1910) 



cate,(Diopside) j 









i * i , . 1 1 1 1 1 1 .i 





a 



a 



tt 



1391 



Allen & 

 White 



32 (1909) 



** Percentages by weight. 



