The happiest specimens of this glass almost rival the wings of butterflies in the brilliancy of their iridescent colours.
Amphioxus is a small fish-like creature attaining a maximum length of about 3 in., semitransparent in appearance, showing iridescent play of colour.
With the exception of the pottery works at Belleek, where iridescent ware of good quality is produced, Fermanagh has no distinguishing manufactures.
The mackerel proper (genus Scomber) are readily recognized by their elegantly shaped, well-proportioned body, shining in iridescent colours.
The plumage of gorgeously-hued birds, the blossoms of flowers (especially the hydrangea), the folds of thick brocade, microscopic diapers and arabesques, are built up with tiny fragments of iridescent shell, in combination with silver-foil, goldlacquer and colored bone, the whole producing a rich and sparkling effect.
Wood has studied the iridescent colours seen when a precipitate of potassium silicofluoride is produced by adding silicofluoric acid to a solution of potassium chloride, and found that they are due to the same cause, the refractive index of the minute crystals precipitated being about the same as that of the solution, which latter can be varied by dilution.
From the labours of his pupil Miotto sprang that branch of the glass trade which is concerned with the imitation of gems. In the 15th century the first crystals were made, and in the 17th the various gradations of coloured and iridescent glass were invented, together with the composition called " aventurine "; the manufacture of beads is now a main branch of the trade.
Calcium carbide, as formed in the electric furnace, is a beautiful crystalline semi-metallic solid, having a density of 2.22, and showing a fracture which is often shot with iridescent "non-automatic."