Micro-WorldGems & Gemology, Fall 2025, Vol. 61, No. 3

“UFO” in Diamond

Michaela Damba

The author recently examined a 3.03 ct Fancy Deep brownish orangy yellow diamond featuring a small feather on the table and very strong yellow color zoning in a stellate pattern. When held table to culet, the diamond displayed a feather that, with its reflection, appeared as a caricature of an unidentified flying object soaring across the sun (see above).

Feathers are common inclusions that impact the clarity grade of a diamond. This diamond received a clarity grade of SI1 based on its etch channels and several feathers. Color zoning does not impact the clarity grade, but it can affect the overall color grade of a diamond.

Michaela Damba is a senior staff gemologist at GIA in Carlsbad, California.

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