M Ferguson and Merwin — The Ternary System. 



Table I. 

 Quenches which locate the boundaries of the fields of stability. 

 Time 

 Composition wt. % Temp. in Phases present 36 Boundary 



CaO MgO Si0 2 °C. min. 



31 



7 



62 



1343 



20 



32 



6 



62 



1370 



15 



23 



14-5 



62-5 



1369 



20 



25-25 



12-5 



62-25 



1350 



20 



28 



10 



62 



1343 



20 



30 



9 



61 



1327 



15 



31 



8-5 



60-5 



1327 



25 



31 



9 



60 



1334 



15 



32 



8 



60 



1344 

 1340 



30 

 20 



33 



10 



57 



1350 



20 



35 



11 



54 



1355 



25 



32 



8 



60 



1344 

 1340 



30 

 180 



35 



11 



54 



1355 



25 



36 



12 



52 



1368 



25 



32 



7 



61 1330-1335 240 



30 



20 



50 



1354 

 1359 



15 



20 



32 



18 



50 



1367 



15 



33 



16-5 



50-5 



1366 



20 



34 



15 



51 



1361 



20 



36 



13 



51 



1352 



15 



23 



22-5 



54-5 



1385 



20 



25 



22 



53 



1388 



20 



29 



20 



51 



1367 



15 



29 



21 



50 



1365 



20 



37 



12 



51 



1366 



15 



38 



11 



51 



1366 



25 



38 



12 



50 



1381 



25 



42-4 



8-8 



48-8 



1403 



15 



44 



8-5 



47-5 



1406 



20 



45 



8 



47 



1409 



15 



47 



7 



46 



1393 



30 



47 



8 



45 



1390 



15 



49 



6 



45 



1379 



20 



50 



5 



45 



1380 



60 



515 



3-5 



45 



1417 



10 



50 



6 



44 



1389 



15 



51 



5 



44 



1410 



15 



Glass -J- trace SiO, 

 Glass 4- aCaO.SiO," 

 Glass -j- trace SiO, 

 Glass -j- trace SiO, -j- trace 



CaO.MgO.2SiO, 

 Glass -(- trace SiO., -j- trace 



CaO.MgO.2SiO, 

 Glass + CaO.MgO.2SiO, 

 Glass + CaO.MgO.2SiO, 

 Glass + CaO.MgO.2SiO, 

 Glass 4- aCaO.SiO, 

 Glass + 5CaO.2MgO.6SiO, -f 



CaO.MgO.2SiO, 

 Glass + 5CaO.2MgO.6SiO, 4- 



trace CaO.MgO.2SiO, 

 Glass 4- 5CaO.2MgO.6SiO, 

 Glass 4- aCaO.SiO, 

 Glass + 5CaO.2MgO.6SiO, 4. 



trace CaO.MgO.2SiO, 

 Glass 4- 5CaO.2MgO.6SiO, 

 Glass + aCaO.SiO, 

 Glass 4- trace SiO, 4- jSCaO.SiO, + 

 5CaO.2MgO.6SiO, 14, 

 No glass + 2CaO.MfirO.2SiO, + 



CaO^Mg0.2S"iO, 

 All glass 



Glass 4- 2CaO.MgO.2SiO, 

 Glass 4- trace 2CaO.Mg6.2SiO, 

 Glass -j- trace 2CaO.MgO.2SiO, 4- 



trace CaO.MgO.2SiO", 

 Glass 4- trace 2CaO.MgO.2SiO, 

 Glass 4- CaO.MgO.2SiO, 

 Glass -1- 2MgO.SiO, 

 Glass 4- CaO.MgO.2SiO, 

 Glass 4- 2MgO.SiO, 4. trace 



CaO.MgO.2SiO, 

 Glass 4- trace aCaO.SiO, 

 Glass -j- trace aCaO.SiO, 

 Glass 4- 2CaO.MgO.2SiO, 

 Glass + aCaO.SiO, 

 Glass 4- trace 2 CaO. MgO. 2 SiO, 

 Glass 4- aCaO.SiO, 

 Glass -j- trace aCaO.SiO, 4- trace 



2CaO.MgO.2SiO, 

 Glass + 2CaOMg0.2Si0 2 

 Glass 4- aCaO.SiO, -f trace 



2CaO.MgO.2SiO, 

 Glass 4- 3Ca0.2SiO, 

 Glass -j- trace aCaO.SiO, 4- 



trace 3Ca0.2SiO, 

 Glass + 2CaO.SiO, 

 Glass 4- 2CaO.SiO, 



15, E 



1, 2 



1, 3 



13, 14 



16 



3, 4 



4, 5 



13, 6 



6, D 



7, C 



30 The formulas of the pure compounds will be given to denote the phases, 

 but in many cases the actual phases have not such compositions, being solid 

 solutions and therefore variable in composition. 



