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Summary table

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





Natural colors

Artificially colored


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



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





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


Type II b, electrical

Type I a, no electrical




Distinguishing features Clarity