MicaCalc automatically calculates muscovite compositions from microprobe analyses.
The results are presented in tables and in various diagrams (Phengite solid solution series, Mu-Pg-Ce diagram, A'KF diagram, AFM (Ms and Kf) diagram. For further details see below.
Using microprobe analyses, this program can be used to automatically calculate muscovite compositions based on 22 oxygen atoms. The oxides, the cations, the lattice site occupancies, the end members Margarite (CaAl₂)[Si₂Al₂O₁₀](OH)₂), Paragonite (NaAl₂)[Si₃AlO₁₀](OH)₂), Celadonite (K(Mg, Fe²⁺)(Fe³⁺, Al)[Si₄O₁₀](OH)₂) and Muscovite (KAl₂[AlSi₃O₁₀](OH)₂), as well as the values for divalent and trivalent iron are calculated (total iron, Fe²⁺, Fe³⁺).
The micas are classified using the Muscovite-phengite-celadonite diagram, the A'KF diagram (A' = [Al₂O₃+Fe₂0₃]-[Na₂O+K₂O+CaO], K = K₂O, F = Fe0+MgO+MnO) and the AFM (Ms and Kf) diagrams.
Furthermore, the micas are presented in a diagram in which the Si content per formula unit (Si/f.u.) is plotted against the aluminum content per formula unit (Al/f.u.) (based on 11 oxygen atoms). The straight line shown in this diagram represents the Phengite solid solution series. The Si content of muscovite can provide information about the physical conditions during metamorphism (“Phengit Barometer”;
see literature).
You can enter the values individually in the table below or use the input fields. Here you enter for up to 5 micas the values (oxides) as rows separated by single spaces (see placeholders; 200 characters max.). Note the order of the elements in the table: Na Mg Al Si K Ca Ti Mn Fe (total Fe as FeO) H₂O Ba Cr! Additionally, the sample designation must come first. You can use the period or the comma as a decimal separator.
You can also enter your data (oxides) here (into the light-blue fields).
Name | |||||
Oxides | Oxides | Oxides | Oxides | Oxides | |
Na2O | |||||
MgO | |||||
Al2O3 | |||||
SiO2 | |||||
K2O | |||||
CaO | |||||
TiO2 | |||||
MnO | |||||
FeO | |||||
H2O | |||||
BaO | |||||
Cr2O3 | |||||
Total | |||||
Temperature selection* | |||||
Temp. [°C] |
* Here you can enter for each mica a temperature (from 500°C to 1100°C max.). This value is used to make a rough pressure estimate with the Phengite barometer. The results are shown in a diagram under "Show Phengite Barometer".
Oxides [wt.-%] | Mol wt. (AW) | Mol-Prop. | Element | Wt.-% | Atom-Prop. | Oxygen | Cations (O=22) | |
---|---|---|---|---|---|---|---|---|
Mica 1 | ||||||||
SiO2 | Si | |||||||
TiO2 | Ti | |||||||
Al2O3 | Al | |||||||
Cr2O3 | Cr | |||||||
MgO | Mg | |||||||
CaO | Ca | |||||||
MnO | Mn | |||||||
FeO | Fe | |||||||
BaO | Ba | |||||||
Na2O | Na | |||||||
K2O | K | |||||||
Total* | *without Water | |||||||
Mica 2 | ||||||||
SiO2 | Si | |||||||
TiO2 | Ti | |||||||
Al2O3 | Al | |||||||
Cr2O3 | Cr | |||||||
MgO | Mg | |||||||
CaO | Ca | |||||||
MnO | Mn | |||||||
FeO | Fe | |||||||
BaO | Ba | |||||||
Na2O | Na | |||||||
K2O | K | |||||||
Total* | *without Water | |||||||
Mica 3 | ||||||||
SiO2 | Si | |||||||
TiO2 | Ti | |||||||
Al2O3 | Al | |||||||
Cr2O3 | Cr | |||||||
MgO | Mg | |||||||
CaO | Ca | |||||||
MnO | Mn | |||||||
FeO | Fe | |||||||
BaO | Ba | |||||||
Na2O | Na | |||||||
K2O | K | |||||||
Total* | *without Water | |||||||
Mica 4 | ||||||||
SiO2 | Si | |||||||
TiO2 | Ti | |||||||
Al2O3 | Al | |||||||
Cr2O3 | Cr | |||||||
MgO | Mg | |||||||
CaO | Ca | |||||||
MnO | Mn | |||||||
FeO | Fe | |||||||
BaO | Ba | |||||||
Na2O | Na | |||||||
K2O | K | |||||||
Total* | *without Water | |||||||
Mica 5 | ||||||||
SiO2 | Si | |||||||
TiO2 | Ti | |||||||
Al2O3 | Al | |||||||
Cr2O3 | Cr | |||||||
MgO | Mg | |||||||
CaO | Ca | |||||||
MnO | Mn | |||||||
FeO | Fe | |||||||
BaO | Ba | |||||||
Na2O | Na | |||||||
K2O | K | |||||||
Total* | *without Water |
Mica 1 | Mica 2 | Mica 3 | Mica 4 | Mica 5 | |
---|---|---|---|---|---|
Grid occupation | |||||
Tetrahedron | |||||
Tetrahedral Al | |||||
Octahedral Al | |||||
Octahedron | |||||
Interlayer | |||||
Total | |||||
Check total
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|||||
The ratio FeO/(FeO+MgO) | |||||
FeO/(FeO+MgO) | |||||
A´KF | |||||
A´ | |||||
K | |||||
F | |||||
Total | |||||
A´KF (*100) | |||||
A´ | |||||
K | |||||
F | |||||
Total | |||||
AFM (Ms) | |||||
A (Ms) | |||||
F | |||||
M | |||||
AFM (Kf) | |||||
A (Kf) | |||||
F | |||||
M |
Mica 1 | Mica 2 | Mica 3 | Mica 4 | Mica 5 | |
---|---|---|---|---|---|
SiO2 | |||||
TiO2 | |||||
Al2O3 | |||||
Cr2O3 | |||||
MgO | |||||
CaO | |||||
MnO | |||||
FeO | |||||
BaO | |||||
Na2O | |||||
K2O | |||||
H2O | |||||
Total | |||||
Cations | |||||
Si | |||||
Ti | |||||
Al | |||||
Cr | |||||
Mg | |||||
Ca | |||||
Mn | |||||
Fe | |||||
Ba | |||||
Na | |||||
K | |||||
Total | |||||
The ratio FeO/(FeO+MgO): X(Fe) | |||||
X(Fe) | |||||
Grid occupation | |||||
Si | |||||
AlIV | |||||
Tetrahedron | |||||
AlVI | |||||
Cr | |||||
Ti | |||||
Fetotal (Fe²⁺) | |||||
Mn | |||||
Mg | |||||
Octahedron | |||||
Ba | |||||
Ca | |||||
Na | |||||
K | |||||
Interlayer | |||||
Total | |||||
End-members | |||||
Margarite
![]() |
|||||
Paragonite
![]() |
|||||
Celadonite
![]() |
|||||
Muscovite
![]() |
|||||
Total | |||||
Phengite component in Muscovite
![]() |
|||||
Phengite | |||||
Muscovite | |||||
Total | |||||
The Phengite-Celadonite-Muscovite diagram | |||||
Paragonite (Pa) | |||||
Celadonite (Ce) | |||||
Muscovite (Mu) | |||||
Total | |||||
Fetot., Fe²⁺, Fe³⁺ | |||||
Fetot. | |||||
Fe²⁺ | |||||
Fe³⁺ | |||||
The A'KF diagram | |||||
A' | |||||
K | |||||
F | |||||
Total | |||||
The AFM(Ms) diagram | |||||
A (Ms) | |||||
F | |||||
M | |||||
The AFM(Kf) diagram | |||||
A (Kf) | |||||
F | |||||
M | |||||
Total | |||||
"Phengite barometer" | |||||
Al/f.u. (11 O) | |||||
Si/f.u. (11 O) | |||||
Additional values [pfu] | |||||
K+Na+Ca (22 O) | |||||
Ti (11 O) | |||||
Fe+Mg (22 O) | |||||
Na/(Na+K) (22 O) | |||||
Na/(Na+K) (11 O) | |||||
Mean values (Mica 1–5) | |||||
Ø Al (11 O) | |||||
Ø Si (11 O) | |||||
Min. Si (11 O) | |||||
Max. Si (11 O) | |||||
Ø Ti (22 O) | |||||
Ø Si (22 O) | |||||
Min. Ti (22 O) | |||||
Max. Ti (22 O) |
Classification of white micas using the Paragonite-Celadonite-Muscovite diagram
Captions
• |
Mica 1 |
• |
Mica 2 |
• |
Mica 3 |
• |
Mica 4 |
• |
Mica 5 |
Top corner |
Paragonite |
Right corner |
Celadonite |
Left corner |
Muscovite |
The white micas in the Si/f.u. vs. Al/f.u. diagram. The straight line shown in this diagram represents the Phengite solid solution series between Muscovite and Celadonite. Higher Si-contents may represent higher formation pressures (see references at bottom of page).
The Si content of the muscovites plotted against temperature. The lines are isobars. The pressure information is in GPa (after Hermann & Spandler, 2008).
Captions
• |
Mica 1 |
• |
Mica 2 |
• |
Mica 3 |
• |
Mica 4 |
• |
Mica 5 |
Pressure-temperature diagram with the isopleths for the Si content per formula unit (Si/f.u.) of the phengites (normalized to 11 oxygen atoms) in the limiting paragenesis with potassium feldspar, phlogopite and quartz. The dashed line shows the stability curve for phengite with 3.3 Si/f.u. according to Velde (1965). The continuous curve at high temperatures marks the upper stability limit of paragenesis. According to Massonne & Schreyer (1987; Fig. 3).
The Micas shown in the A'KF diagram. For infos see captions below. After Ehlers & Blatt (1982).
Captions
• |
Mica 1 |
• |
Mica 2 |
• |
Mica 3 |
• |
Mica 4 |
• |
Mica 5 |
Bottom corner |
F = Fe0+MgO+MnO |
Red dot bottom corner |
Antophyllite, Opx |
Dark green field |
Chlorite |
White dot in dark green field |
Almandine |
Top right corner |
K = K₂O |
Purple dot top right corner |
K-feldspar |
Red dot at end of phengite line |
Muscovite |
Top left corner |
A' = (Al₂O₃+Fe₂0₃)-(Na₂O+K₂O+CaO) |
Green dot top left corner |
Kyanite, Andalusite, Sillimanite |
The Micas shown in the AFM(Ms) diagram. For infos see below. After Nelson, S.A. (2011).
Captions
• |
Mica 1 |
• |
Mica 2 |
• |
Mica 3 |
• |
Mica 4 |
• |
Mica 5 |
The AFM(Ms) diagram The AFM(Ms) diagram. From Nelson, S.A. (2011). |
The Micas shown in the AFM(Kf) diagram. For infos see below. After Nelson, S.A. (2011).
Captions
• |
Mica 1 |
• |
Mica 2 |
• |
Mica 3 |
• |
Mica 4 |
• |
Mica 5 |
The AFM(Kf) diagram The AFM(Kf) diagram. From Nelson, S.A. (2011). |
Current date
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A small, not very current selection. There are also newer publications on this topic on the Internet (e.g.).