How much art and science, and what attention, what care is necessary to render the sun-beams which are imprisoned in a tiny polyhedron of pure carbon, brilliant and sparkling! – Charles Blanc, Art in Ornament and Dress, 1875, translated from French

Now the melancholy God protect thee, and the tailor make thy garments of changeable taffeta, for thy mind is opal. – William Shakespeare, The Twelfth Night

The aquamarine… has the glassy tint of the waves of the sea. – Charles Blanc, Art in Ornament and Dress, 1875, translated from French

The opal resembles a fraction of the rainbow softened by a milky cloud. – Charles Blanc, Art in Ornament and Dress, 1875, translated from French