Understanding diamond inclusions

[ajoh3142]

Hi All - When looking at a diamond with a loupe I can see a feather in the pavillion (lower girdle facets) that I think is reflected into the upper girdle facets. I think this because when I turn the diamond to the side the feather in the upper girdle facets disappears, but when I look at the diamond straight down from the table there clearly is a feather region in the upper girdle facets. Is what I am describing a possible reflection of the feather - do inclusions generally reflect like this?

 

[kenny]

- do inclusions generally reflect like this?

They can.
It depends on where the inclusion is.

Diamond has a very high amount of a cool optical property, Index of Refraction.
It is how much light changes angle when it strikes a surface on the diamond.

This, and how a diamond has many facets, means a polished diamond is particularly good at "projecting" inclusions so they appear in other facets and views in surprising ways.

Once in a while one inclusion (unfortunately positioned) will appear many many times and look like many inclusions.
The exact same inclusion, if it were placed in a more fortunate location, would not appear so many times.
I believe grading labs do take this into account when determining the clarity grade.