|
STANDARD
GRADING TABLE FOR MUSCOVITE MICA SPLITTINGS
|
|
GRADE
|
QUALITY
|
AREA
OF USABLE
RECTANGLE+
|
MINIMUM
DIMENSION OF ONE SIDE OF USABLE RECTANGLE
|
THICKNESS
OF 10 SPLITTINGS
|
|
sq cm
|
sq cm
|
cm
|
inches
|
mm
|
inches
|
| No
2 |
Book
Form Dusted Loose
|
96.8
tlt* 154.8
96.8 tlt 154.8
|
15
tlt* 24
15 tlt 24
|
5.1
5.1
|
2
2
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.005 to 0.009
|
| No
3 |
Book
Form Dusted Loose
|
64.5
tlt 96.8
64.5 tlt 96.8
|
10
tlt 15
10 tlt 15
|
5.1
5.1
|
2
2
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
4 |
Book
Form Dusted Loose
|
38.7
tlt 64.5
38.7 tlt 64.5
|
6
tlt 10
6 tlt 10
|
3.8
3.8
|
15
15
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
4.5 |
Book
Form Dusted Loose
|
28.8
tlt 38.7
28.8 tlt 38.7
|
4.5 tlt 6
4.5 tlt 6
|
3.2
3.2
|
1.25
1.25
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
5 |
Book
Form Dusted Loose
|
19.4
tlt 38.7
19.4 tlt 38.7
|
3
tlt 6
3 tlt 6
|
2.5
2.5
|
1
1
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
5 Top |
Book
Form Dusted Loose
|
14.5
tlt 19.4
14.5 tlt 19.4
|
2.25
tlt 3
2.25 tlt 3
|
2.2
2.2
|
0.875
0.875
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
5 |
Book
Form Dusted Loose
|
12.8 tlt 19.4
12.8 tlt 19.4
|
2
tlt 3
2 tlt 3
|
2.0
2.0
|
0.8
0.8
|
0.15
to 0.23
0.15 to 0.23
|
0.006
to 0.009
0.006 to 0.009
|
| No
6 |
Book
Form Dusted Loose
|
6.4 tlt 12.8
6.4 tlt 12.8
|
1
tlt 2
1 tlt 2
|
1.9
1.9
|
0.75
0.75
|
0.18
to 0.25
0.18 to 0.25
|
0.007
to 0.009
0.007 to 0.009
|
| No
6 |
First
Loose
|
To
pass over a screen having 2.2 sq cm
or 0.875 sq inch openings.
|
0.18
to 0.28
|
0.007
to 0.011
|
| No
6 |
Second
Loose
|
To
pass over a screen having 1.6 sq mm
or 0.625 sq inch openings.
|
0.18
to 0.28
|
0.007
to 0.011
|
| No
6 |
Third
Loose
|
To
pass over a screen having 1.3 sq cm
or 0.50 sq inch openings
|
0.18
to 0.28
|
0.007
to 0.011
|
| No
6 |
Cheap
Loose
|
To
pass over a screen having 064 sq cm
or 0.25 sq inch openings
|
0.18
to 0.30
|
0.007
to 0.012
|
|
+ The area specified
refer to the maximum usable rectangle (usable area) that may be
cut from the specimen and not on the total area. The sheets shall
not be of minimum area specified but shall contain a fair proportion
of sizes throughout the specified range
*
tit to less than
|