The phrase "an expression of sadness" is correct and usable in written English.
You can use it when discussing feelings, emotions, or artistic representations that convey sadness.
Example: "The poem is a poignant reflection, serving as an expression of sadness over lost love."
Alternatives: "a display of sorrow" or "a manifestation of grief."
On Ms. Smith it seems an expression of sadness.
Levinson claims that the obvious suggestion here is that the funeral march is 'readily-hearable-as' an expression of sadness.
Therefore, "Mottainai" is an expression of sadness and guilt over the disrespectful and wasteful treatment of valuable entities.
However, there was also an expression of sadness among the providers when describing the severity of the complications experienced by young girls.
Crying can be an expression of sadness, pain, fear, joy, or just pure emotion, and it's a natural, healthy way to let those emotions run through our bodies.
The minister paused for a moment and an expression of deep sadness crossed his face.
There seems to be on his face, and in his deep set eyes, an expression of profound sadness and disillusionment.
Arledge's relationship with Cosell ends in an expression of "irrepressible sadness" for a man he addresses as "impossible friend".
Anna Akhmatova was immensely dignified, with unhurried gestures, a noble head, beautiful, somewhat severe features, and an expression of immense sadness.
Maybe too, through the metaphor of the interjection, his apology is broader, an expression of shared sadness for the ways our various media have claimed to bring us together when they've done more of the opposite, and that his art has to be part of that noise in its hope to somehow bridge the resulting gulfs between us.
They viewed 30 pictures of dynamic facial expressions changing slowly from a neutral face to a prototypical expression of sadness, disgust, surprise, fear, anger, or happiness in 25 steps.
