liquid

eutectic

miscibility gap

solvus

melting Tof albite

melting Tof orthoclase

400

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

% Ab

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

single K-feldspar

solidsolution

single Na-feldspar

solidsolution

two feldspars

liquid

400

500

700

900

600

800

850

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

% Ab

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

100% liquid

400

liquid

500

700

900

600

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

800

liquidAb Or49 51

100% liquid

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

750

liquidAb Or49 51

100% liquid

400

liquid

500

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

700

liquidAb Or49 51

100% liquid

675

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

liquidAb Or53 47K-feldspar

Ab Or09 91

91% liquid9% K-feldspar

650

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

liquidAb Or59 41K-feldspar

Ab Or14 86

75% liquid25% K-feldspar

625

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

liquidAb Or64 36K-feldspar

Ab Or21 79

65% liquid35% K-feldspar

600

400

liquid

500

700

900

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

liquidAb Or68 32K-feldspar

Ab Or40 60

32% liquid68% K-feldspar

595

400

liquid

500

700

900

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

K-feldsparAb Or45 55

89% K-feldspar11% Na-feldspar

Na-feldsparAb Or82 18

590

400

liquid

500

700

900

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

85% perthite15% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18K-feldspar

Ab Or

(exsolution)43 57

Na-feldsparAb Or

(exsolution)84 16

perthite contains5% exsolution

lamellae

antiperthite contains5% exsolution

lamellae

575

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

79% perthite21% antiperthite

perthite contains14% exsolution

lamellae

antiperthite contains12% exsolution

lamellae

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18K-feldspar

Ab Or

(exsolution)38 62

Na-feldsparAb Or

(exsolution)87 13

550

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

70% perthite30% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains22% exsolution

lamellae

antiperthite contains14% exsolution

lamellae

K-feldsparAb Or

(exsolution)32 68

Na-feldsparAb Or

(exsolution)90 10

525

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

67% perthite33% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains27% exsolution

lamellae

antiperthite contains16% exsolution

lamellae

K-feldsparAb Or

(exsolution)26 74

Na-feldsparAb Or

(exsolution)93 07

500

400

liquid

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

67% perthite33% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains31% exsolution

lamellae

antiperthite contains18% exsolution

lamellae

K-feldsparAb Or

(exsolution)22 78

Na-feldsparAb Or

(exsolution)95 05

475

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

61% perthite39% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains32% exsolution

lamellae

antiperthite contains18% exsolution

lamellae

K-feldsparAb Or

(exsolution)19 81

Na-feldsparAb Or

(exsolution)96 04

450

400

liquid

500

700

900

600

800

1000

Or

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

60% perthite40% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains35% exsolution

lamellae

antiperthite contains19% exsolution

lamellae

K-feldsparAb Or

(exsolution)17 83

Na-feldsparAb Or

(exsolution)97 03

425

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

60% perthite40% antiperthite

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18

perthite contains36% exsolution

lamellae

antiperthite contains19% exsolution

lamellae

K-feldsparAb Or

(exsolution)15 85

Na-feldsparAb Or

(exsolution)98 02

400

liquid

500

700

900

600

800

1000

Or Ab

20 40 60 80 1000

KAlSi O3 8 NaAlSi O3 8

Tem

pe

ratu

re°C

KAlSi O -NaAlSi O System at 500 MPa (5 Kbar)3 8 3 8

singlefeldspar

singlefeldspar

two feldspars

K-feldsparAb Or

(exsolution)14 86

Na-feldsparAb Or

(exsolution)98 02

89% perthite11% antiperthite

perthite contains37% exsolution

lamellae

antiperthite contains20% exsolution

lamellae

PerthiteAb Or

(overall)45 55

AntiperthiteAb Or

(overall)82 18