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Summary table

SUMMARY TABLE: Distinguishing features under the spectroscope and microscope of natural and artificially colored diamonds

 

 

 

color

Natural colors

Artificially colored

Yellow

All hues

All hues, gold-yellow to amber colors,

 

often very "oily" appearance

 

Yellow line 415.5 clear,

Lines at 498, 504, 594 nm

 

other lines of the

plus lines of the yellow series

 

yellow spectrum weaker

 

Brown

All hues

a) Brownish to purple

 

 

b) Yellow-brown to deep brown

 

Clear line at 504 nrn,

a) Diagnostic: 594 nm clear

 

accompanied by a weaker

weaker lines at 637,620,

 

double line at

610 nm and possibly yellow line

 

498 and 537 nm

b) Equal strength double line at

 

 

498 and 504 nm and possible yellow

 

 

line

Green

Very rare

Umbrella effect or dark ring

 

 

in the girdle

 

 

.

 

Line at 504 nm clear,

Pair of lines at 498 and 504 nm

 

498 nm weaker or not

of equal strength and possibly

 

present at all

yellow line

Blue

Type II b, electrical

Type I a, no electrical

 

semi-conductor

conductivity


Distinguishing features Clarity