Russian grading system for fancy-cut diamonds
MARQUISE

Group

À

B

n=Ar/Br

1.7-2.4

1.6-2.6

Weigth, ct.

Optimal

äî 0.49

îò 0.50

1.05

îò 0.10

Toler.limits

-

-

±0.05

-

br, %

Optimal

60

60

60

60

Toler.limits

±5

±5

±5

±5

hr, %

Optimal

2.0

2.0

2.0

2.0

Toler.limits

+1.0
-0.5

-1.3

-1.3

+1.0
-1.3

a

Optimal

33°

33°

33°

33°

Toler.limits

+2°
-3°

+2°
-3°

±3°

±3°

b

Optimal

41°

41°

41°

41°

Toler.limits

+1°
-2°

+1°
-2°

+1°
-2°

+1°
-2°

BAQUIETTE

Group

À Á

n=Ar/Br

from 1.4

from 1.4

br, %

Optimal

60

60
Toler.limits

±10

±10

hr, %

Optimal

2

2

Toler.limits

±1

±1

a

Optimal

40°

40°

Toler.limits

±5°

±5°

a1

Optimal

24°

24°

Toler.limits

±6°

±6°

b

Optimal

50°

50°

Toler.limits

±5°

±5°

b1

Optimal

41°

41°

Toler.limits

±2°

±2°

b2

Optimal

36°

36°

Toler.limits

±2°

±2°

EMERALD

Group

À
n=Ar/Br

1.5 – 1.75

br, %

Optimal

60

Toler.limits

±10

hr, %

Optimal

2.0

Toler.limits

±1.0

Cr, %

Optimal

22.5

Toler.limits

±2.5

a

Optimal

40°

Toler.limits

+5°
-2°

a1

Optimal

35°

Toler.limits

±2°

a2

Optimal

24°

Toler.limits

±6°

b

Optimal

50°

Toler.limits

±5°

b1

Optimal

41°

Toler.limits

±2°

b2

Optimal

36°

Toler.limits

±2°

j

Optimal

45°

Toler.limits

±5°

PEAR

Group

A B

n=Ar/Br

1.4-1.7

1.4-1.7

1.4-1.7

1.4-1.7

Ìàññà, ct.

Optimal

äî 0.49

îò 0.50

1.05

îò 0.10

Toler.limits

-

-

±0.05

-

br, %

Optimal

60

60

60

60

Toler.limits

±5

±5

±5

±5

hr, %

Optimal

2.0

2.0

2.0

2.0

Toler.limits

+1.0

- 0.5

-1.3

-1.3

+1.0

- 1.3

a

Optimal

33°

33°

33°

33°

Toler.limits

+2°

-3°

+2°

-3°

±3°

±3°

b

Optimal

41°

41°

41°

41°

Toler.limits

+1°

-2°

+1°

-2°

+1°

-2°

+1°

-2°

OVAL

Group

À

n=Ar/Br

îò 1.2
up to 1.6

br, %

Optimal

60

Toler.limits

±5

hr, %

Optimal

2

Toler.limits

±1

a

Optimal

33°

Toler.limits

±3°

b

Optimal

41°

Toler.limits

+1°
-2°

Optimal values and tolerance limits br and hr in % from Br.