This test tile pictured here is nothing special. No pigments, no wild fluxes; just feldspars and silicates. Why then, with the most basic of materials, with the complete lack of colorants, we find a blush of blue?
Within the animal kingdom blue is a rarity. Even the bluest of blue whales is still technically grey. To be blue is to stand out of the pack. Only one animal species produces a “true” blue pigment; the rest, they have to come up with other means.
Morhpo didius has a blue that sings. A blue that tickles the cones of your eyes finer than any gold jewelry. A colour made afresh from each new angle. This neotropical butterfly seeks to clothes itself in the very finest of ultramarines. Each angle of this butterfly's wings cuts through with new unique hues. It is a display that glimmers with a vibrancy that we can't help but envy. It is here we will find the answer to our bubbles of blue glaze.
Zoomed in we no longer see the wing as a homogeneous plane but a tiled tessellation of tiny scales. Like minute crinkle-cut chips stacked against each-other, each scale is covered with microscopic ribbed plates.
The wavelength of blue light has an interval of 450-495 nanometers. Morpho Didius' layers are spaced between these exact dimensions. When light rays hit the wing the rays bounce around in the corrugated valleys only to be shone back at us with a new blue look. The size of these voids dictates the hue like the length of a piano wire dictates the note.
A colloid is a medium filled with a finely suspended materials. In the case
of this glaze it is a colloid filled with finely dispersed bubbles of gas. Sulfates, fluorides, chlorides and carbonates love to froth at high temperatures. If the glaze is thick enough at the right heat, it will capture and store these globules of gas. Looking at these blue blooms of glaze I know there are microscopic bubbles too small for me to see individually, but just the right size for me to see a blue iridescent glow. These bubble's dimensions directly correspond to the size of Morhpo didius' scales and thus produce the same effect. Iridescent blues will always be my favourite; Empty voids the exact right size for light to bounce back with a blue pop.
The feathers of a peacock and the shine of an oil spill will always draw me in. Iridescents are so intriguing, they make you want to view every angle, see each new vibration of colour, appreciate each new shade of blue. In these petrified bubbles there is a void for light to dance at the right tempo. They show you how beautiful an empty space can be. The harmony of electromagnetic frequencies and echoes of empty space is what draws me into the void, that empty space constantly being filled with a blue aura.