Todays Guess It Poem!!

Here's tonights guess it poem, do you know what it is??

This beautiful half moon,
a curvation oh so bright.
For some it may come easy,
To others an enduring fight.
Once captured,
Unforgettable.
Once lost,
Truly regrettable.
A worthy line,
to catch the eye.
even appears,
On those who are shy.
So take a part of me with you,
When you see.
This life strengthened helix,
That rests upon me.