। ॥
In plain words
O Kāmākṣī, the sapphire is only a stone, the blue lily wilts by day, and a cloud is dark only now and then. So there is nothing to compare with the beauty of your sidelong glance.
Word for word
A stone merely the sapphire; by days wilting the lily shows; occasional the cloud-darkness; hence your, Kāmākṣī, empty the comparison for the eye-corner-beauty.