Royal Zenith Sapphire

The blue of European royal court dress and regalia from the late seventeenth century forward — the color of British peers' robes, French royal sashes, the lining of the crown-jewel cases. The color refers to a saturated, slightly violet-shifted blue with the matte finish of velvet or melton wool dyed to maximum intensity: deeper than cornflower, warmer than ultramarine, with the heraldic weight of a color reserved for monarchs and the official Crown.

Arabic samt-al-ra's, path-overhead. As a color modifier, zenith implies an overhead-pointing-and-high-point quality, the visual register of celestial-sphere-and-overhead-Zenith hand-overhead-pointing-and-high-point celestial-sphere-and-overhead-and-Zenith-pole zenith-and-overhead-pointing-and-high-point surfaces under celestial-sphere-and-overhead-and-Zenith-pole astronomical-and-celestial-mechanics overhead-axis-light. Sits at the modifier-and-cosmic end of the grid, parallel to nadir and axis in usage.

An iron-and-titanium-bearing corundum — the same mineral as ruby, hardness 9 on the Mohs scale, mined for two millennia from Sri Lanka, Burma, Madagascar, and the Cashmere mines of British India. The color refers to a fine Kashmir-cut sapphire: a saturated, slightly violet-shifted deep blue with the gem's signature internal velvet — a quality of light scattering in the stone that faceted glass cannot replicate. Cooler than cobalt, deeper than azure.