Thou foolish Hafiz! Say! do churls
Know the worth of Oman's pearls?
Give the gem which dims the moon
To the noblest, or to none.
It is a late echo of the scriptural saying, "Cast not your pearls before swine." No modern poet shows more knowledge of the nature, or a more just appreciation of the delicate beauty of the gem than Emerson. In his "May Day," speaking of the tardiness of the spring, he writes: "Slow grows the palm, too slow the pearl."
Evidently he knew of the slow process by which the successive coats of filmy nacre increase the size of the growing gem. Likewise a couplet in "Nature" betrays the poet's observation of the iridescent nature of the colors in mother-of-pearl, and in the gem occasionally when those fleeting tints are added to the beauty of its luster; the lines are a dainty illustration:
Illusions like the tints of pearl,
Or changing colors of the sky.
Some of the great poets, notably Tennyson, apparently confuse the gem with its mother-of-pearl, or refer to the latter only when they speak of pearl. In his "Recollections of the Arabian Nights," however, Tennyson in describing one of his beauties evidently refers to the gem:
And a brow of pearl